University of Southern California Dissertations and Theses

Early Eocene to early Miocene planktonic foraminiferal biostratigraphy of the western Indian ocean

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Early Eocene to early Miocene planktonic foraminiferal biostratigraphy of the western Indian ocean

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Content EARLY EOCENE TO EARLY MIOCENE PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY OF THE WESTERN INDIAN OCEAN by Robert London Fleisher A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (Geological Sciences) June 1975 UMI Number: DP28533 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI Dissertation Publishing UMI DP28533 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProOuest ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 U N IV E R S IT Y O F S O U T H E R N C A L IF O R N IA THE GRADUATE SCHOOL UNIVERSITY PARK LOS ANGELES, CALIFORNIA 90007 This dissertation, w ritten by .....ROBERT LONDON FLEISHER under the direction of his.... Dissertation Com mittee, and approved by a ll its members, has been presented to and accepted by The Graduate School, in p a rtia l fu lfillm e n t of requirements of the degree of D O C T O R O F P H I L O S O P H Y DISSERTATION COMMITTEE * CONTENTS Page ABSTRACT............................................ vi INTRODUCTION ....................................... 1 Purpose and scope ............. 1 Acknowledgments ••••••• 8 PREVIOUS W O R K ..................................... 10 Indian Ocean micropaleontology .............. 10 Interregional systems of planktonic foraminiferal zones ....................... 13 GEOLOGIC SETTING ................................... 16 Site locations ............. 16 Geotectonic considerations •• • 20 Sedimentary facies •••••••• ......... 23 Site 2 1 9 ................................... 23 Site 220 ................................... 23 Site 237 ................................... 32 PROCEDURES.......................................... 36 Sample terminology ............................ 36 Sample preparation •••••••• ......... 37 ii Page DEEP SEA PLANKTONIC PORAMINIFERAL ZONES IN THE INDIAN OCEAN..................................... 4l Approaches to planktonic biostratigraphy . . . 4l Usefulness of the Bolli and Blow-Berggren zonations in deep-sea sequences ............ 45 Proposed deep-water zonation .................. G e n e r a l ..................................... 49 Early M i o c e n e .............................. 51 Oligocene................................... 60 Late E o c e n e ................................ 71 Early and Middle E o c e n e ................... 75 SYSTEMATICS.......................................... 92 Introduction ..................................... 92 Comments on surface wall texture .............. 101 Species descriptions ............................ 104 PLATES................................................. 270 REFERENCES............................................ 299 APPENDIX.............................................. 326 iii ILLUSTRATIONS Figures Page 1. Location map of selected western Indian Ocean Deep Sea Drilling Project Sites . . . 17 2, Stratigraphic sequence at Deep Sea Drill ing Project Site 2 1 9 ..................... 26 3# Stratigraphic sequence at Deep Sea Drill ing Project Site 220 29 4. Stratigraphic sequence at Deep Sea Drill ing Project Site 237 3^ 5. Correlation of selected Early Miocene zonation syste ms....................... 53 6. Correlation of selected Oligocene zonation systems....................................... 62 7# Correlation of selected Late Eocene zona tion s y s tems................................ 73 8. Correlation of selected Early and Middle Eocene zonation systems ..................... 76 9. Correlation of selected Early Eocene to Early Miocene planktonic foraminiferal zonation systems ............................ 88 10. Correlation of sequences at Sites 219, 220, and 237 with, proposed deep sea zonation systems....................................... 90 11. Phylogenetic pattern of coarsely perforate species of "Globigerina. 11.................. 148 iv Table 1. Page Location and recovery data for Deep Sea Drilling Project Sites 219, 220, and 237 • • 19 v ABSTRACT The widely accepted systems of* biostratigraphic zonation for Cenozoic planktonic foraminifera have been based very largely on the study of* stratigraphic sections deposited along continental margins. Examination of* foraminiferal populations recovered from deep-sea sedi ments, however, has emphasized the extensive and selective dissolution of calcareous skeletal debris. The tests of many species are largely or completely removed from open- ocean foraminiferal thanatocoenoses. Many of the standard zones are based upon forms particularly susceptible to dissolution; as a result, no single zonation system is suitable for widespread application to tropical deep sea faunal sequences. To provide the basis for a suitable zonation of this sort, planktonic foraminiferal populations of late Early Eocene to Early Miocene age were studied from sedi ments recovered at three Deep Sea Drilling Project loca tions in the equatorial western Indian Ocean. Two of these, Sites 219 and 220, are closely associated with the Chagos-Laccadive Ridge, slightly southwest of the southern tip of India. The third, Site 237» lies in a shallow saddle on the Mascarene Plateau, farther to the south. At none of the three locations is the stratigraphic sequence complete and uninterrupted, but among them, all but a portion of the mid-Oligocene is represented. Fifteen planktonic foraminiferal zones based upon faunal events involving solution-resistant species can be recognized over this interval, and thirteen are represent ed in sediments recovered at the three sites. Most of the zones spanning the Late Eocene through Early Miocene have been adopted or modified from pre-existing zonations, al though no single system included them all. Faunas of this age are typically non-diverse even within deposits from tropical continental margins; many of the zones defined from such deposits can be recognized in tropical Indian Ocean deep-sea sequences. A few exceptions include zones based on Catapsydrax stainforthi. Globoquadrina tapurien- sijs, and Hantkenina (Cribrohantkenina) inf lata. These species are rare in deep-sea sequences because of their pronounced susceptibility to dissolution. Three new zones are introduced to represent inter vals in the early Middle and Early Eocene. These in clude : 1. Globigerinatheka curryi - G. euganea Zone, defined as the interval between the final ap pearance of Morozovella aragonensis and the initial appearance of Orbulinoides beckmanni vii and thus equivalent to the widely-used Morozo- vella lehneri Zone, M. lehneri is extremely rare, probably because of dissolution; the new zone can be recognized by the presence of either or both of the nominate species in the absence of M, aragonensis and 0. beckmanni, 2. Morozovella coronata - M. aragonensis Zone, de fined by the stratigraphic overlap of the ranges of these two species. This zone is very closely equivalent to the combined Globigeri- natheka subconglobata and Hantkenina (H,) aragonensis Zones of general usage, but these cannot be recognized in the deep-sea because of the very poor preservation of the latter two species, 3* Globigerinatheka senni Zone, which includes the interval containing this species prior to the initial appearance of M, coronata. The G. senni Zone approximately correlates with the Acarinina bullbrooki Zone (which is difficult to recog nize because of the poorly-defined prevalent concept of the nominate species) and with the Globanomalina palmerae Zone (which has not been observed in deep-sea sediments because of the high dissolution susceptibility of G. palmerae), viii All fifteen zones are based upon widely distributed solution-resistant species, and the zonation proposed here should have broad application to tropical deep-sea strati graphic successions. INTRODUCTION Purpose and Scope In the spring and summer of* 1972, R/V Glomar Challenger conducted drilling operations at eleven sites (during Legs 23 and 2k) in the Arabian Sea and tropical western Indian Ocean, The material collected at these sites is of* considerable importance because the tropical Indian Ocean has received substantially less attention from geologists and micropaleontologists than have the other major low-latitude oceanic basins. It is in this context that studies of the plank tonic foraminifera from Leg 23 and Leg 2k samples should be regarded. Bandy e_t al. (1972) listed and categorized the bulk of the reports published prior to the avail ability of Deep Sea Drilling Project (DSDP) samples and data. Most of these studies are of limited scope and essentially local interest. Extensive investigations by Russian authors (notably, Beliaeva, 1964), however, and subsequently by Boltovskoy (1969), Be and Tolderlund (l97l)> and Zobel (1973) have helped to delineate the distributional patterns of modern planktonic populations as reflected in tows and surface sediments, and to 1 clarify the relationship between these populations and modern water masses. Fossil planktonic foraminiferal assemblages, in contrast, remain poorly known. Most piston core studies have dealt very largely with latest Neogene and Quaternary faunas, and have examined these associations primarily in terms of glacial and post-glacial climatic and oceano graphic fluctuations (e.g., Vincent, 1972). The few ac counts of pre-Pliocene planktonic faunas recovered from piston cores (Herman, 1963; Saito and Van Donk, 197^) are no more than isolated occurrences. An extensive uncon formity on the modern sea floor along the southeastern margin of Africa, with resultant exposures of Miocene and Pliocene sediments (Vincent, 1972), has not been studied in detail. Thus from a biostratigraphic standpoint the pre- Quaternary planktonic foraminiferal faunas from the western Indian Ocean were virtually unknown prior to DSDP activity in this region. The preliminary description of Leg 23 foraminiferal suites (Fleisher, 197^a) represents the first extensive account of Tertiary assemblages from this basin. The problems which were encountered in the prepara tion of the preliminary study, however, provided insights into the difficulties involved in working with deep-ocean faunas, and the necessity of dealing with these problems provided the incentive for this report. 2 Long stratigraphic sequences which contained relatively diverse and well-preserved planktonic foramini feral assemblages were recovered at only two— Sites 219 and 220--of the six sites drilled in the Arabian Sea dur ing Leg 23* The Neogene biotas present at Site 219 in Cores 1 through 14 present no exceptional problems except in the Pliocene and late Early Miocene (Fleisher, 197^n), where modifications of the definitions of Blow’s (1969) Zones are necessary. Throughout the early Middle Eocene to mid-Oligocene interval at Site 219, however, and the Early to early Middle Eocene sequence at Site 220, faunal ages were consistently difficult to determine in terms of the widely-used zonation systems of Blow (1969), Bolli (1966a), and Berggren (l972a). Nonetheless, every effort was made to recognize these standardized zones as defined; Fleisher (l97^a, P* 1003) felt that it was inappropriate "to propose a zonation based upon what is effectively a single stratigraphic section . . . #" In great measure this qualification no longer ap plies. The availability of samples from Site 237 (Leg 2h), where a thick sequence of upper lower Eocene to lower Miocene sediments was continuously cored with generally excellent recovery, permits a comparison of faunal suc cessions from locations within the same climatic regime. In addition, published data concerning the Paleocene to Early Miocene foraminiferal faunas from Legs 22 (McGowran, 3 197**; Berggren et al• , 197*0 » (Heiman e_t al. , 197*0 * and 25 (Sigal, 197*0 allow similar comparisons to be made over a broader area among sites representing a number of geologic and oceanographic environments. The present study, then, comprises an examination of the late Early Eocene to Early Miocene planktonic foraminiferal biostratigraphy from three sites (219* 220, and 237) in the tropical western Indian Ocean. In part, because this region has not been studied in detail, the treatment is necessarily descriptive. Equally important, however, is the confrontation and solution of the bio- stratigraphic problems recognized in the preliminary study (Fleisher, 197*+a) and reinforced here. These problems fall into three broad categories: 1. Taxonomic difficulties. Many of the species concepts applied to Paleogene forms appear to be unusually ill-defined; this is particularly true for some species of the Paleocene to Middle Eocene genera Acarinina and Morozovella. One important example of this systematic ambiguity is the treatment accorded to "Globorotalia” (i.e., Acarinina) bullbrooki Bolli. Examination of illu strations of the forms referred in the literature to this taxon suggests that in many cases the name has been used rather indiscriminately for virtually any early Middle Eocene conicotruncate acarininid. Unillustrated or poorly illustrated reports of this species must thus be consider- k ed unreliable in the absence of evidence to the contrary* The evaluation of reports of this species is further com plicated by its treatment variously as a junior synonym of A* hensa (Cushman) or A. spinuloinflata (Bandy), or both (e.g., Berggren, 1968). The species concepts of a number of other stratigraphically important taxa, including among others Morozovella lehneri (Cushman and Jarvis), M, spinulosa (Cushman), Acarinina broedermanni (Cushman and Bermudez), Turborotalia boweri (Bolli), and Globigerina- theka kugleri (Bolli, Loeblich, and Tappan), are equally ill—defined. A corollary of this taxonomic problem is the low number of species names applied to Early Tertiary faunas, particularly in pre-Late Eocene assemblages. Morphologi cally valid and (potentially) stratigraphically signifi cant species appear to have been either included within the overly broad concepts of pre—existing taxa or simply not reported. A judgment of this sort is of course sub jective, and probably relates as much to questions of taxonomic philosophy as of observation and perception. Nonetheless, Fleisher (l97^a) felt justified in erecting seven new species for Eocene morphotypes, all of which were morphologically distinctive and common to abundant throughout much of their observed range. Test dissolution and faunal reduction. Xt is now widely recognized, after the seminal work of Berger (1970), that selective dissolution of foraminiferal tests is a persistent and important factor in the modification of deep-sea thanatocoenoses. The effect of this process is to reduce the diversity of deep-ocean assemblages to a degree roughly dependent upon the intensity of dissolution. As a result, these assemblages are not directly comparable to continental-margin faunal suites. 3# Recognition of zonal boundaries. Most systems of biostratigraphic zones for Tertiary planktonic foramini- fera are based, to one extent or another, on the zonations developed by Bolli (1966a) and Blow (1969)# Both of these, however, were very largely or entirely developed from the stratigraphic record of fossil sequences in land-based sec tions, most of which represent ancient continental-margin deposits. To the extent that test dissolution has been a factor, however, deep-sea associations differ significantly from continental marine sequences in the loss, prior to burial, of the remains of most or all specimens of some species. In practice, the widely—used biostratigraphic zones proved unrecognizable throughout a number of inter vals because of the absence of many of the key taxa. Blow's (1969) Zone P. 16 (Late Eocene), for instance, is based on the total range of Hantkenina (Cribrohantkenina) inflata, a form recognized from a number of marine sequences exposed on the continents. A single specimen was recognized in the sediments at Site 219; this virtual 6 absence led Fleisher (197**-&) to postulate a minor uncon formity representing this zone* It now appears that the absence of H. (CJ. ) inf lata is due to its susceptibility to dissolution rather than to the non-deposition of sediments; it has not been observed at Site 237> or at Site 214 on the Ninetyeast Ridge (McGowran, 197^)• Similar problems have been noted, here and by other authors, with the application to deep-sea sediments of several of the Early and early Middle Eocene zones of Bolli (1966a)• The best solution appears to be the erection of a set of zones recognizable in deep-sea sequences* No zonal scheme, certainly, will be uniformly applicable, even within similar climatic and paleoceanographic regimes. A continuum stretches from the complete absence of solution effects— a situation probably non-existent in basinal marine sediments— to the complete pre-burial destruction of all foraminiferal tests. No set of zones, clearly, would be suitable to the full range of this continuum; beyond a cer tain point the precision of relative age determination de creases, and the span of zones increases, as more species are selectively removed. Nonetheless, it has proved possible to recognize a series of biostratigraphic zones applicable to deep-sea sequences in which dissolution has had relatively strong effects. A zonation of this sort has been proposed (Jen kins and Orr, 19719 1972) for the late Late Eocene to 7 Pleistocene of the eastern tropical Pacific Ocean; the system proposed here represents a modification and exten sion of this Pacific zonation. Acknowledgments The author feels a keen sense of appreciation to the late Dr. Orville L. Bandy, through whose help participa tion in DSDP Leg 23 was made possible. Dr. Bandy also served as research director during the preliminary phase of this work, and his comments and suggestions were parti cularly helpful. Dr. Edith Vincent provided many of the samples from Site 237 j as well as much related information and advice. This report would have been all but impossible without her patient help and cooperation. The following people provided valuable criticism during the preparation of this study, and their contributions are gratefully ac knowledged: V. C. Meyer, W. A. Berggren, R. G. Douglas, J. L. Lamb, and J. Hardenbol. Discussions with P. L. Steineck were particularly important in shaping and clari fying the concepts of planktonic foraminiferal taxonomy propounded here. R. Hockett and J. Mouton of Exxon Pro duction Research Company prepared the scanning electron mi c ro graphs. Finally, special thanks are due to the authorfs friends and colleagues at the University of Southern Cali fornia, without whose help and support at critical junc- 8 tures the completion of this report would have been im possible. This study was supported under Oceanographic Section, National Science Foundation NSF Grant GA-3^1^5> and was carried out using the facilities of the University of Southern California Micropaleontology Laboratory and of the Allan Hancock Foundation. 9 PREVIOUS WORK Indian Ocean Micropaleontology The paucity of* studies dealing with the Early Tertiary of the tropical western Indian Ocean has been noted above. Bandy et^ al. (1972) cited only two published reports of the recovery of Paleogene planktonic foramini feral faunas; another has recently appeared. The bio stratigraphic significance of these recoveries, however, insofar as they bear directly upon the conclusions reached in this report, is limited. Herman (1963) and Saito and Fray (1964) did little more than note that Paleogene faunas had been observed in core samples, although Herman included a brief list of Cretaceous and Paleocene species. Saito and Van Donk (1974) dealt primarily with Cretaceous and Early Tertiary paleoclimatic events through an investi gation of the oxygen isotope paleotemperatures of plank tonic foraminifera. All of their Paleogene samples, how ever, were of Danian (Early Paleocene) age, an interval not examined here. In addition, the piston cores which form the basis of all three studies were obtained from a rela tively restricted geographic locality (Agulhas Plateau - Mozambique Ridge - Mozambique Channel) characterized by 10 intensive current scour and considerable sedimentary and faunal mixing (Vincent, 1972). Saito and Fray (1964) re marked that their Early and Middle Eocene faunas contained no keeled globorotaliid species, an observation that sug gests an extra-tropical origin for these assemblages (Bandy, 1964, 19675 McGowran, 1974) in contrast to the (apparently) fully tropical suites discussed below. Results from the study of planktonic foraminiferal faunas in Deep Sea Drilling Project samples are still pre liminary, but a considerable amount of data has become available. McGowran (1974) discussed the results from Leg 22, in the eastern Indian Ocean. Particular emphasis was given to those sites (214, 216, and 217) located along the Ninetyeast Ridge which contained well-developed and well- preserved planktonic suites. Particular consideration was also given to faunas of Paleocene through Middle Eocene age at the expense of younger populations. Berggren et al. (1974) also examined material from Leg 24. The sampling interval which they employed was considerably larger than that used by McGowran, however, and more attention was paid to Oligocene and Neogene assemblages. Fleisher (1974a) examined in some detail the plank tonic populations from Leg 23, in the Arabian Sea. At only two sites, 219 and 220, were sequences penetrated con taining extensive faunas suitable for careful analysis. These sections have been re-examined in part and are dis- 11 cussed below. Heiman e_t aLL. (197*0 briefly summarized the plank tonic biostratigraphy for Leg 2k, including range charts of stratigraphically important species. Vincent (197*0 dis cussed the significance of these findings for an under standing of the regional geology. Finally, Sigal (197*0 and Zobel (197*0 briefly described the Early Tertiary foraminiferal faunas recovered during Leg 25* and related the Paleogene biostratigraphy of the DSDP sites to strati graphic records of the surrounding land areas. These sites are considerably farther south than the Leg 23 and Leg 2k locations examined here, and the foraminiferal faun as do not appear to be directly comparable. This conclu sion is difficult to evaluate, however, because Sigal provided no detailed range charts, and post-Early Eocene faunas were treated in a relatively cursory manner. Krasheninnikov (1969) Sigal (197*0 Lave sum marized the available literature treating the planktonic foraminiferal biostratigraphy around the margins of the western Indian Ocean. Foraminifera from East African sequences, for the most part, are poorly known; most of the references cited by Sigal are either unpublished or too old to be of direct value to planktonic studies, or deal primarily with other types of micro-fossils. The most significant study of East African planktonic foramini fera is that of Blow and Banner (1962), from the Lindi area 12 of* Tanganyika, Blow incorporated many of the conclusions reached in that study into his later and more extensive work (Blow, 1969)# Paleogene sediments are well known in outcrop and in the subsurface of the Cauvery Basin of southeastern India, particularly in the region of Pondicherry, Raju (1968, 1970> 1971) has described in detail the planktonic foraminifera from these sediments, and has developed a detailed zonation for the Paleogene through Early Miocene, Banerji and Mohan (1970) presented an alternative set of planktonic foraminiferal zones for strata in this region. Interregional Systems of Planktonic Foraminiferal Zones From the intensive studies of planktonic foramini feral populations conducted during the last two decades, two sets of what may be termed "standard" interregional zones have emerged. Generally similar, these systems differ in a number of details; most workers have utilized one or the other of them, Bolli* s original (1957a, 1957t>* 1957c) zonation has been modified somewhat (1966a) but remains in very wide use. Blow's (1969) zonal system for the late Middle Eocene to Holocene has also gained broad acceptance, probably in part because of the mnemonic value of the "number-letter" nomenclatural system he employed, Berggren (1971a, 1972a) has applied this system to Bolli*s 13 Paleocene through Middle Eocene zones to provide a uniform ly designated series of zones for the entire Cenozoic. Some authors (e.g., Jenkins and Orr, 1972) have objected to the "abbreviated letter and number method of naming the zones” on the grounds that such terminology violates pro per stratigraphic procedure. All of these zones, however, have been properly defined (Blow, 1969)* The number-letter zone terminology probably should be considered as a mnemonic device, and more formal zone names are available if their use appears justified. Jenkins and Orr (l971j 1972) concluded from the study of their eastern tropical Pacific samples that many of these "standard" zones cannot be recognized in the deep sea because of the selective dissolution of many of the critical species. They therefore proposed a zonation for the late Late Eocene to Pleistocene, based very largely upon solution-resistant forms, which they were able to correlate with Bolli*s series. Blow (l970a) discussed in detail the philosophical and practical considerations involved in the establishment and use of biostratigraphic systems. Consonant with these considerations, his zones, like those of Bolli, fall for the most part into one of three types: partial range zones, total range zones, or concurrent range zones. An alternative approach, however, has been proposed by van Hinte (1969a, 1969b) and expanded by Berggren (l971h, ik 1972b). Zones are based on the stage of phyletic develop ment achieved by different lineages of planktonic fora- minifera; thus a given population may be representative of several different zones, depending upon how many lineages are utilized. This system of overlapping "phylozones" has been termed "multiple phylogenetic zonation" by Berggren (l971b), and has great potential value as a tool in cor relation. On the other hand, its successful application requires large quantities of data because this application requires that the zones accurately reflect the full ranges of the species used (van Hinte, personal communication). Xt may well be correct to conclude that sufficient data are available to apply this approach to Neogene popula tions, as Berggren (1972b) has in part done. Xn light of the uncertainties, discussed above, in taxonomy and species ranges, it appears quite premature to define zones of this type for the Paleogene. It is also an improper use of this approach to construct multiple phylogenetic zones on the basis of only a few stratigraphic sections in a single geo graphic region, unless all evolutionary transitions are ob served. In the absence of this unlikely circumstance (Eldredge and Gould, 1972), no attempt has been made to utilize this approach. 15 GEOLOGIC SETTING Site Locations Sites 219 and 220, occupied and drilled during Deep Sea Drilling Project Leg 23, lie in the vicinity of the Chagos-Laccadive Ridge west of the southern tip of India. Location and recovery data are presented in Figure 1 and Table 1. The Chagos-Laccadive ridge is a north-south trend ing structure extending southward from the eastern margin of the Arabian Sea to its intersection with the Central Indian Ridge at approximately 10°S. In the eastern Arabian Sea, much of the length of this structure consists of shoal areas and banks at depths less than 1500 m,which constitute the Chagos, Laccadive, and Maldive Island groups. Between the shoals, water depths are commonly on the order of 2000 m and occasionally as deep as 4000 m. Site 219 is located in one such gap at a depth of 1764 m, between the Laccadive and Maldive Islands. Site 220, located approximately 2.5° south and 2° west of Site 219, lies on the western flank of this ridge, at a depth slightly greater than 4000 m. Site 237, a location occupied during Leg 24, lies 16 Figure 1 Location map of selected western Indian Ocean Deep Sea Drilling Pro ject Sites. Contours are in meters. .4000 Seychelles B an k s X" Saya De * 0 ~^\ Malha_ °0 B an k 55 60 65 70 75 18 Table 1. Location and recovery data for Deep Sea Drilling Project Sites 219* 220, and 237. SITE 219 SITE 220 SITE 237 L A T IT U D E 0 9 ° 0 1 .75' N 0 6 ° 30.97' N 0 7 °0 4 .9 9 'S L O N G IT U D E 7 2 °5 2 .6 7 'E 7 0 ° 5 9 .0 2 'E 5 8 °0 7 .4 8 'E W A TER DEPTH (M) 1764 4043 1623 NO. OF CORES 31 21 67 P E N E T R A T IO N <M)a 411 350 627 R E C O V E R Y (M )a 223 101 312 A G E b Late Paleocene Early Eocene Early Paleocene 3 including sediments and basalt b age of lowest dated fossil assemblage 19 at a depth, of 1628 m in a saddle between the Seychelles Bank and Saya de Malha, on the Mascarene Plateau. The origin and geologic nature of this plateau is a matter of controversy, and a primary (but unachieved) objective in drilling at this site was the determination of the age and nature of the basement. Geotectonic Considerations Recent investigations of sea floor spreading in the Indian Ocean have documented the geotectonic complexity of the western Indian Ocean and Arabian Sea. The geologic history of this basin and the significance of many of the large-scale geologic features remain poorly understood. An extensive discussion of the evolution of the Indian Ocean is beyond both the scope and the needs of this re port, and would be largely speculative in any case. Some aspects of this evolution, nevertheless, bear directly on the paleontological considerations, particularly insofar as they deal with the relative locations of the three sites. One such aspect is the geologic nature and geo tectonic significance of the Chagos-Laccadive Ridge. Fisher jet aJ.. (l97l) summarized much of the basic evidence available to deal with this question; these data are discussed in more detail by McKenzie and Sclater (l97l)* Magnetic anomalies in the northern Arabian Sea, which can 20 be related to Early Tertiary portions of the standard sequence of paleomagnetic reversals proposed by Heirtzler et al* (1968),^ correlate with identical anomalies south of India* Both anomaly patterns trend east—west, and their location and orientation suggests a cumulative offset of approximately 3000 km (Vhitmarsh, 197^)* These anomalies, and the presence of a transform fault in the Arabian Sea parallel to the Chagos-Laccadive Ridge, have been cited as evidence that the ridge functioned as a transform fault during the Early Tertiary (Fisher et al#, 197l)* Whether or not the ridge behaved in this manner has considerable significance for interpreting the paleoposition of Sites 219, 220, and 237* If there has been considerable transform displacement across the ridge, the modern proximity of Sites 219 and 220 suggests that the paleo- latitudes at which the underlying oceanic crust was formed were considerably different. In view of the overall off set of the anomaly patterns, the present-day relative positions of the two sites also implies that the basement age at Site 219 is considerably greater than at Site 220# The difference in age, in this model, reflects the time during which Site 219 moved northward to a location ad jacent to Site 220* This sequence of paleomagnetic reversals will hence forth be cited as the Heirtzler reversal time scale. 21 On the assumption that this ridge behaved like a transform fault, at least during the Paleogene, Fisher et al. (1971) reconstructed the geometry of the west-central Indian Ocean. This reconstruction (their Fig. 9) implies that Site 237* on the Mascarene Plateau, was located much closer to the other two sites during the Paleogene; sub sequent movement has separated them along a northeast- southwest axis. Drilling has confirmed that the basement at Site 219 is indeed older than at Site 220, as the transform- fault model appears to predict. It is not clear, however, that the discrepancy in ages is sufficiently great. The lowermost sediments recovered at Site 219, deposited in shallow water and probably little younger than basement, are only 7 m.y. older (Berggren, 1972a) than the strata just above basement at Site 220. It is possible that the present geographic separation of the two sites is suf ficiently great to account for this difference, but in any case it does not appear that major offset between them is necessarily indicated. In opposition to the view that the ridge is a trans form structure, Morgan (1972) interpreted it as a hot-spot ridge formed by the movement of the Indian plate over a mantle plume. Whitmarsh (197^0 adduced two lines of evi dence to support this conclusion. In the first place, drilling results in the western Arabian Sea demonstrate 22 that the Owens Fracture Zone functioned as a transform fault during the Paleogene, If the Chagos-Laccadive Ridge behaved similarly, it should be "parallel” to the Owens structure, and it clearly is not. Furthermore, the hot spot model implies that the age of volcanism should de crease southwestward along the Chagos-Laccadive Ridge, The evidence is not conclusive, particularly because igneous basement was not penetrated at Site 219* but radiometric age determinations from island exposures suggest that the postulated trend is correct (Whitmarsh, 197^)• In the absence of definitive evidence, the Morgan- Whitmarsh hot-spot model is tentatively accepted here, largely because of the basement-age arguments cited above. This assumption implies that any mid-Tertiary re organization of plate motion was probably much less in tense than that suggested by the transform—fault model. The relative positions of Sites 219 and 220 are thus taken to have remained unchanged during the Cenozoic; Site 237* on the other hand, has been moved southwestward relative to the northern sites by subsequent spreading across the Carlsberg Ridge. Sedimentary Facies Site 219 Three lithologic units were observed in the Paleo gene sedimentary sequence at this site. The basal 111 m, 23 recovered from Hole 219A, consists of greenish-gray and black semilithified and partially recrystallized limestone, and is of P.4 (Late Paleocene) age. The common rotaliid and larger foraminifera reflect the neritic origin of these deposits, and planktonic foraminifera are scarce (Mamgain et al,, 1974)• The benthic foraminiferal fauna in these sediments is essentially identical to assemblages reported in Paleocene (Rajagopalan, 1968) strata from Pondicherry, South India (Gowda, 1964), Igneous basement was not reached. Above Core 27* in Hole 219* a major discontinuity separates Paleocene sediments below from lower Eocene above (in Core 26), This hiatus is roughly similar in position to those noted at Leg 22 sites on the Ninetyeast Ridge, Pimm (1974) recognized the neritic environment in which these sediments were deposited and concluded that the observed hiatuses were a response to the action of purely shallow-water processes, Vincent e_t al. (1974), however, recognized an unconformity of approximately the same age at Site 238, in sediments with a postulated paleodepth of approximately 2600 m. If these occurrences are reflections of a regional event, the causal factor is not at present apparent. Recovery was poor in the Lower Eocene sediments in Cores 22 through 27 at Site 219, and they have not been considered in this report. Chert is common in this inter- 24 val, particularly in the upper two cores; most of the sediment, however, consists of chalk and limestone, grayish- yellow to yellow-brown in color (Whitmarsh et al., 197^a). The remainder of the recovered Paleogene section consists of nannofossil oozes and chalks with varying foraminiferal and radiolarian contents. Radiolarians are almost absent above the very lowest Oligocene, in Core l6, but are abundant below that level to Core 21, just above the chert. Sedimentation rates are particularly high (70 m/m.y.) in the shallow-water sequence of Hole 219A, but decrease markedly in the overlying deep-water deposits. The extent to which the decrease was gradual is unclear, but by the Middle Oligocene sediment was accumulating at no more than 5 m/m.y. Site 220 Site 220 lies within a quiet magnetic zone on the western flank of the Chagos-Laccadive Ridge. The basal cores recovered basalt with distinct chilled margins and vesiculation, and at least six separate flows appear to be represented (Whitmarsh e_t al., 197^b). Because these flows have had no discernible effect on the immediately overly ing sediment, and because sedimentary layers intercalated with the basalts are few, thin, and limited to the upper portions of the recovered sequence, the basalt is taken to 25 Figure 2 Stratigraphic sequence at Deep Sea Drilling Project Site 219* Recovered intervals are shown in black* SITE 219 D E P T H (M) 1 50 — 200 A G E C O R E E A R L Y E A R L Y 1b 10 LATE 1 7 18 M ID D L E 19 20 21 LITHOLOGY N a rin ofo ssil-rich fo ra m m ife ra l 0 0 /0 arid chalk F o ra m m ife ra -ric h n annofossil 00/e and chalk R a d io la ria n -ric h nan n o fo ssil ooze and chalk 27 represent igneous basement. Regional magnetic patterns are difficult to interpret, especially in that no anomalies are present in the immediate vicinity,, but the site appears to lie between anomalies 6 and 23. Thus the maximum age for the oldest sediments at Site 220 should be 58 m.y. (Heirtz ler e_t al. , 1968), or perhaps 4-5 m.y. younger if the modi fications to the Heirtzler reversal time scale suggested by Sclater e_t aJL. (1974) and Schlich (1974) are accepted. This corresponds well with the age of the oldest recovered fossiliferous sediment, Early Eocene Discoaster lodoensis Zone, approximately 50-51 m.y. (Boudreaux, 1974). Approximately 110 m of Lower and Middle Eocene sedi ments was recovered from above the basalts. No massive chert was penetrated, but thin stringers occur sporadically throughout the lower 40 m. Radiolarians and foraminifera are relatively common in the nannofossil oozes and chalks that make up this interval, but preservation is only fair to poor in the chert-rich Lower Eocene. All faunas from this interval are very largely pelagic, and this location lacks the shallow-water history of Site 219. The Late Eocene (Core ll) and Oligocene (Cores 6 through 10) are represented by radiolarian-bearing nanno fossil oozes. Foraminiferal faunas, however, are sparse, intensely dissolved, and relatively nondiverse. They are completely absent in the Upper Eocene sediments recovered in Core 11. 28 Figure 3. St rati graphic sequence at; Deep Sea Drilling Project Site 220, Recovered intervals are shown in blade, SITE 220 D EPTH (Ml AG E C O R E L IT H O L O G Y — 100 — 150 — 200 — 250 — 300 ■350- Lale 5 1 10 Late 11 M iddle Early 1 7 19 U N D A T E D J L 20 21 Nannofossil oo^e and chalk Radiol arian-rich nannofossil o o /e and chalk, w ith th in ash beds and chert near top Nannofossil chalk and th in chert beds Basalt flows w ith th in interbedded sediments The pattern of variation in sedimentation rate is broadly similar to that observed at Site 219. Initial sediment accumulation was relatively rapid (20-^0 m/m.y.) during the Early and Middle Eocene, a period when the site presumably lay near the crest of the spreading center. Movement away from the ridge crest, together with crustal plate cooling, resulted in sinking of the sea floor (Sclater et al., 197l)• This model predicts a decrease in sedimentation rate with time for any section of the sea floor unless the sinking is reversed or halted (presumably through a reorganization of plate movements), unless sedi ment supply increases (through an increase in productivity or in the contribution of non-biogenous sources), or un less the lysocline (Berger, 1970) is displaced deeper in the water column. None of these qualifications appears to apply to Sites 219 or 220, although a minor increase in accumula tion rate appears in the Late Oligocene. Sedimentation de creased progressively during the Middle Eocene and most of the Oligocene. Whitmarsh e_t al. (l97^b) attempted to re late this decrease to movement of the sea floor away from an area of coastal upwelling. High productivity associated with this zone was considered to be reflected in the rela tively high percentage of biogenic silica (in the form of radiolarians). One of the more striking discoveries of the Deep Sea Drilling Project studies, however, has been the 31 geographically extensive distribution of* radiolarian-rich sediments during the Eocene, particularly the Early and Middle Eocene. An analysis of* the possible causes of* this well-documented expansion of radiolarian populations is beyond the scope of, and not directly relevant to, this report, but it seems unlikely that the distribution of these forms in Site 220 sediments is primarily controlled by a process as local as coastal upwelling. Site 237 The lower 3h0 m of section recovered at Site 237 consists of recrystallized and partly silicified fine grained limestone probably formed by the diagenetic altera tion of nannofossil ooze. Chert layers and stringers are sporadically present throughout. Foraminifera are rela tively common (5—15 percent) in the section, but are poorly preserved except in a few horizons. Although planktonic foraminifera are typically dominant, neritic forms and reef detritus, including larger foraminifera (Discocvclina) and coralline algae, are present in at least four Upper Paleo cene horizons. Fisher ejt aJ.. (197*0 suggested that this basal sequence "is almost certainly a very thick shallow- water calcareous assemblage," but careful examination of the benthic foraminiferal populations (Vincent e_t auL. , 197^) ^as clearly shown that the neritic faunal elements represent allochthonous slumped material. The deepest 32 assemblages in most samples are upper bathyal in the Early and early Late Paleocene, deepening to lower bathyal by latest Paleocene and Early Eocene time. The admixture of shallow-water detritus is probably responsible for the high sedimentation rate (approximately 68 m/m.y.) that prevailed during much of the Paleocene (P.l-2 through P.^). With deepening and the termination of major slump ing in the Late Paleocene and Early Eocene, the sedimenta tion rate slowed markedly at this site. Vincent et al. (197^0 postulated continuous deposition across the Paleocene-Eocene boundary. Largely because of the silici- fied and recrystallized nature of much of the sediment, however, core recovery was insufficient to preclude the existence of an unconformity spanning the boundary, similar to those found on the Ninetyeast Ridge and at Sites 219 and 236. No direct evidence supports the pre sence of such an hiatus, however; these authors interpret ed the slower sedimentation rate in this interval as a re flection of the onset of separation between the Saya de Malha and the Chagos-Laccadive Ridge (see above, and Fisher et al.. 197l)* Overlying Middle Eocene through Lower Miocene sedi ments consist largely of nannofossil oozes. Foraminifera are present throughout, but are relatively rare in the Late Eocene and uncommon in the Oligocene. 33 Figure h Stratigraphic sequence at Deep Sea Drilling Project Site 237* Recovered intervals are shown in black. 3^ SITE 237 D E P T H (M ) C O R E Late M id d le L IT H O L O G Y Foraminifera-rich nannofossil ooze and chalk N a n n o fo s s il ooze and c h a lk I— 300 35 PROCEDURES Sample Terminology The manner in which Deep Sea Drilling Project operations are conducted has necessitated the development of a sample designation system particularly suited to these procedures# In order to avoid confusion, this terminology is briefly described here# Each segment of drill pipe used aboard the R/V# Glomar Challenger is 9 m long, as is, therefore, each single core, the stratigraphic sequence collected in a full segment of pipe. Each core is numbered sequentially, from the top of each hole; cores with no recovered sample nonetheless receive a number, but drilled intervals, in which no attempt was made to recover material, do not. When brought aboard ship, each core is cut into six 1.5-ni parts, each termed a "section.” The sections are numbered, from one to six, from the top of each core, and the location of an individual sample is expressed in terms of the distance in centimeters below the top of the section. Sample designations reflect the collection and storage procedure. The location of a particular sample can 36 be uniquely indicated by citing the Site number— DSDP sites are numbered consecutively, with, no reference to the Leg number— the Core and Section numbers, and the sampling interval. As used below, therefore, the notation "Sample 219-19-6, 51-53 cm” designates a sample taken from an interval 51 to 53 cm below the top of Section 6, in Core 19, recovered at Site 219# In a few instances, more than one hole is drilled at a single site; these holes are numbered, for example, 219* 219A, and so forth. Finally, for samples taken from the core catcher located directly below the bottom of each core, the desig nation "CC" replaces the section and sample numbers. Sample Preparation Most of the samples utilized in this study were collected aboard ship, either by the author on Leg 23 or by Edith Vincent on Leg 2h0 One sample was taken from each section; where feasible, the same interval was sampled in each section. Ideally, therefore, the distance between successive samples is 1.5 ra. Each section of DSDP core is split longitudinally aboard ship, and one portion is reserved for storage and reference. Samples were taken from the other ("working") half by pressing into the sediment a hollow plastic cylinder approximately 2 cm in diameter. Each sample taken in this fashion is thus a cylindrical plug; the average 37 volume of material contained in these plugs is roughly 5 cubic cm. Core catcher samples are typically larger and more irregular in volume because the sample is already sufficiently churned that no precautions need be taken to prevent additional stratigraphic mixing. Each sample was soaked in water and washed on a 250 mesh (6lyu) Tyler screen. Dry weights were not measured prior to washing, in part because accurate weights were not available for samples washed aboard ship and in part because of the limited time available for the prepara tion of the preliminary report. As a result, it has not been possible to calculate values for foraminiferal number (specimens per gram of dry weight). Most samples disaggregated readily in water with mechanical agitation. More lithified samples, however, were treated with warm hydrogen peroxide, a technique which was effective in breaking down compacted sediments contain ing relatively high quantities of organic matter. There is no evidence to suggest that any of the foraminiferal faunas were damaged by this treatment, which was generally of short (l-2 hours) duration. Samples which did not re spond to this treatment were boiled for 1-2 hours in a dilute solution of Quaternary ”0" (Zingula, 1968); again, no evidence was observed to suggest that any specimens were damaged by this technique. Finally, most samples from cores from Leg 23 (but not from Leg 2^) were subjected very 38 briefly to ultrasonic vibrations. Washed residues were collected in filter paper and dried in a warm (JlOO°C) oven. These dried samples, con sisting largely (in most cases) of foraminiferal tests and radiolarian skeletons, were separated into two size fractions through an 80 mesh (177 /0 Tyler screen. Each fraction in turn was randomly split into a manageable size, strewn on a 7 by 11 cm picking tray, and examined under a binocular microscope. For each sample a list was compiled of the plank- tonic species observed in each size fraction. After the list was constructed, the strew was briefly re-examined to gain a subjective estimate of the relative abundance of each species. Five relative abundance categories were utilized: Very Rare: Only a single specimen was observed. Rare: Specimens were only rarely encountered; in practice, this usually indicates less than a half-dozen specimens observed. Few: The species was somewhat more common, but was still observed only occasionally. Common: At least one specimen, and frequently more, was observed on most of the squares of the picking tray. Abundant: This category is reserved for those in stances in which one or a very few species completely 39 dominate a fauna. Most frequently this occurred in fine- fraction assemblages. Each size fraction was observed separately, and a composite relative abundance was estimated for those forms present in both. No attempt is made here to minimize the entirely subjective nature of these abundance categorizations. It is likely that other investigators, even using the criteria described above, would reach different evalua tions in a number of instances, and that in all probability these criteria have not been applied here with entire con sistency. Nonetheless, it is hoped that the use of these approximations will provide workable estimates of the relative abundance of the species observed. The only true alternative approach, species counts of at least 300 specimens, is prohibitively time-consuming in view of the number of samples involved. By contrast, the number scale adopted by Berggren €rfc al. (197^0 as an expression of abundance would denote a quantitative appearance which is in this instance unjustified. ko DEEP-SEA PLANKTONIC FORAMINIFERAL ZONES IN THE INDIAN OCEAN Approaches to Planktonic Biostratigraphy The publication of U. S. National Museum Bulletin 215 (Loeblich e_t al. , 1957) effectively marks the begin ning of the widespread use of planktonic foraminifera in biostratigraphic studies, although their value had been recognized by some industrial micropaleontologists for several years previously. These forms subsequently have been employed in the solution of problems of correlation in many parts of the world, and as a result the outlines of planktonic foraminiferal evolution have become in creasingly well known, particularly for Neogene as semblages. Two basic approaches have developed toward the application of these fossils to such problems. Benthic foraminifera have been used for many years to correlate strata within relatively localized regions. Usage of this type demands acceptance of the assumption that conditions throughout the region under consideration were sufficiently uniform at any given time to produce homogeneous foraminiferal populations. If this assumption 41 is not met, very precise facies reconstruction is required for accurate correlation. In a region of even minor structural complexity, a reconstruction of this sort is difficult or impossible to make in the absence of independently derived and recognized time lines* Because of the nature of the habitat occupied by these forms, the distribution of benthic foraminifera is very closely related to variations in the bottom environ ment. Although depth, as a representation of a point in space, should not be regarded as a primary factor con trolling benthic foraminiferal faunas (Gibson, 1967, 1968), trends in species distribution commonly appear to parallel variations in paleobathyinetry (e.g., Bandy and Arnal, 1969). The effects of environmental parameters not directly related to depth— nature of substrate, food supply, and surface temperature, among others— are more difficult to recognize, but are certainly significant as well. Except to the extent that they are intolerant of shallow depths, planktonic foraminifera are largely independent of the direct influence of the bottom environ ment. In nearshore localities the proximity of land and the influence of freshwater runoff may affect the faunal abundance and species composition (Phleger, i960), but generally the distribution of planktonic species is very largely related to water mass patterns (Jones, 1968; 42 Cifelli and Smith, 1969)* In continental-margin deposits, therefore, with the exception of nearshore environments, planktonic foraminiferal populations tend to be relatively uniform over much broader areas than are benthic associa tions. Zonations based on planktonic species thus are well suited in general to regional correlation systems. Whether the species ranges correspond to those reported from elsewhere is much less important than whether they are consistent within the region under consideration. Cor relation with European stages or with other regions may prove difficult— the New Zealand stages of Jenkins (l97l)> for instance, may be related to tropical zonation systems only with difficulty--but this correlation may be unneces sary for practical purposes if local stages can be de fined and recognized. In the last two decades, local zonation systems of this sort have been proposed for a large number of geographic regions; a few of the more relevant zonal schemes will be discussed in a later section. Bolli1s (1957a, 1957b, 1957c) initial series of zones was of this nature, in that it was proposed on the basis of observations of fossil populations in stratigraphic sections in Trinidad with little reference to other geo graphic areas. Subsequent work by many authors (e.g., Hillebrandt, 1962, 1965; Luterbacher and Premoli Silva, ^3 1964; Bolli, 1964, 1966b; Bolli and Bermudez, 1965) has indicated that this system, with suitable modifications and additions (Bolli, 1966a), can be widely applied to Tertiary assemblages in tropical regions. The somewhat different series of zones proposed by Banner and Blow (1965a) and Blow (1969) for the late Middle Eocene to Holocene was similarly based on observations from a wide range of geographic localities. With the addition of the Paleocene and Eocene zones proposed by Berggren (1971a, 1972a), this zonation also appears to have broad applic ability within the tropics. The more broad the series of observations upon which a zonation system is based, the more accurately, presumably, it will reflect the evolutionary series upon which, ultimately, it is founded. The Blow-Berggren and Bolli zone series function, therefore, as a standard frame of reference with which less complete local successions can be compared and through which they can be correlated. The system of zones developed, for instance, by Raju (1970, 197l) for the Cauvery Basin cannot be directly ap plied in Egypt, for which Beckmann e_t al. (1969) have pro vided an alternative and local biostratigraphic sequence. These two sequences can nonetheless be compared because both can be correlated moderately closely with the Bolli sequence. In the absence of direct evidence of the evolu tionary transitions, there is no way of evaluating the 44 synchroneity of the same fossil events in the two regions, but this problem is generally true of most stratigraphic sequences (Scott, 1965; Jenkins, 1965a). Usefulness of the Bolli and Blow-Berggren Zonations in Deep-Sea Sequences The assumption can be made with some degree of con fidence that the Blow—Berggren and Bolli intercontinental zonation systems approximate an accurate overall picture of the development of tropical Cenozoic planktonic foraminiferal faunas, particularly with respect to first appearances if not to extinctions (Blow, 1970a)• Neither of these zonations, certainly, represents an ultimate solution to the problems of foraminiferal correlation and biostratigraphy. Bronnimann and Resig (l97l)» Berggren (1973)9 and Cita (l973)» among others, have proposed a number of modifications for Blow’s (1969) Neogene zones, and at least one of Blow’s zone boundaries (N.4/P.22) ap pears to reflect a misinterpretation of the geology at the stratotype (Aquitanian) section (Scott, 1972). Neverthe less, with the recognition that such modifications will continue to become necessary as more data become available, these two zonations are the best interregional correlation systems in wide use. Kleinpell (1972), in a sharp criticism of ’ ’mundial" (i.e., interregional) planktonic foraminiferal correla- 45 tions, suggested that many planktonic zones are "as often as not • . • just a teilzone or biozone based on a single taxon rather than a Zone based on the multiple strati— graphic ranges of taxa that £enhancej its degree of prob ability commensurately" (p. 110) , This objection is some what extreme, but adverse environmental conditions may locally restrict species ranges and induce erroneous cor relations with sequences in other areas. Blow (l970a) re sponded to this line of objection by defending his em phasis on the use of "rapidly developing evolutionary first appearances probably the best means of defining sensibly isochronous surfaces • • •" (p. 259), but he nevertheless urged that environmental conditions should be examined critically before his system was applied to a particular region, Xn practice, evolutionary transitions between species are rarely observed for most phyletic sequences in most stratigraphic sections; there is usually no unequivocal indication that the initial occurrence of a species in a given section is indeed an "evolutionary first appearance," If the Eldredge-Gould (l972) model of specia- tion is broadly correct, the initial occurrence of a planktonic species in widely distributed stratigraphic sections would be virtually isochronous only if initial dispersal of the newly-evolved morphotype is rapid. This assumption is widely accepted (Blow, 1970a) as a working model, but its validity has not been carefully documented, hG The context of Blow's (1969) discussion leaves no doubt that his reference was to environmental factors in fluencing the habitat of planktonic foraminifera, i.e., the paleoceanography of the upper few hundred meters of water. He neglected to consider, however, that in the deep sea the effects of the depositional environment are super imposed on variations in the habitat environment to deter mine the species composition of the thanatocoenose. Berger (1968, 1970) documented the selective solution of modern planktonic foraminiferal species, and Savin and Douglas (1973) showed that the susceptibility of a foraminiferal test to post-mortem dissolution is in part a function of the magnesium content of the test. In populations de posited in deep water, tests of solution-resistant species are concentrated on the sea floor, and some particularly susceptible species are removed altogether. It has become apparent from Deep Sea Drilling Pro ject results (Jenkins and Orr, 1972; Berggren e_t al. , 197^» Fleisher, 197* * - a ) that serious difficulties are involved in attempting to utilize the standard intercontinental zona tion systems for deep-sea assemblages. Both the Blow- Berggren and Bolli zonations were constructed very largely from observations of land-based marine sections deposited along continental margins, where dissolution has had very limited effect on the faunas. The most readily dissolved species, generally, are among those living in near-surface 47 water's (Berger, 1968, 1970)* A number’ of* the zones in both systems are defined on the basis of easily dissolved species, and these zones as defined are unrecognizable in the deep-sea sediments of Legs 23 and 24. All preliminary reports to date of Early Eocene through Early Miocene planktonic foraminifera from tropical Indian Ocean Deep Sea Drilling Project material have at tempted to apply the Blov-Berggren zones to the strati graphic sequences. In general, the results have been un satisfactory. McGowran (1974), for instance, was able to recognize only 9 of 16 zone boundaries in the interval be tween Zones N.7 and P.8 at Site 2l4 on the basis of the defining criteria cited by Blow (1969) or Berggren (1971a, 1972a). Two of these, in fact, were controlled by the short-lived presence of a single species (Orbulinoides beckmanni). Similar problems were encountered in the sequences from the three sites discussed here. Originally, all three successions were correlated with the Blow- Berggren scheme, but the difficulties entailed in age determination clearly indicate the necessity of a zonation specifically developed for partially dissolved deep-sea sediments. Jenkins and Orr (1971* 1972) were also unable to recognize many of the Blow-Berggren or Bolli zones in their DSDP samples from the eastern tropical Pacific Ocean. These authors erected 18 planktonic foraminiferal zones to span 48 the Upper Eocene to Pleistocene interval. The zonation proposed below includes many of their zones, and extends the deep-sea zonation system into the Early Eocene. Proposed Deep-Water Zonation General The zones employed here for the Early Eocene to Early Miocene are defined on the basis of species which from observation and from reports in the published litera ture appear to be relatively resistant to solution. That is, they are usually present in deep-water assemblages of the appropriate age. Several important limitations in the use of this system, however, must be noted. In samples where solution has been particularly intense, the precision with which age determinations can be made is drastically reduced because of the destruction of most of the species originally present in overlying waters. No attempt has been made here to measure the intensity of solution, if indeed such measurement is pre sently possible, but it appears likely that the proposed zonation can be satisfactorily applied only to samples with FS values (Berger and von Rad, 1972) of 6 or less. There is no indication that the biocoenoses from which these fossil assemblages are derived have been any thing but tropical or subtropical throughout the sampled 49 interval. The ecological parameters controlling the dis tribution of modern planktonic species are very poorly known on either a large (Be and Hamlin, 1967; Be and Tolderlund, 197l) or small (Parker, 1965; Boltovskoy, 197l) scale. This ignorance is much more nearly complete for Paleogene distributions than for the Neogene. Although it seems probable that temperature is only one of several oceanographic factors controlling these patterns, climatic generalizations retain a broad level of significance as terms of faunal characterization. Middle and high latitude deep-sea associations of this age are as yet poorly known except for the work of Berggren (1972b) and Berggren and Amdurer (1973) in the North Atlantic. It is not yet clear whether the zones proposed here can be extended safely to extratropical Early and Middle Tertiary populations. It is also probably unwise to attempt to apply a deep-sea zonation to continental-margin sequences. There is reason to believe that resistance to dissolution is cor- related»at least in some cases, with a relatively deep habitat. Resistant species may be absent from fossil as semblages deposited in neritic or upper bathyal depths. Similarly, the absence of key species may result from the disruption of water masses in the vicinity of continental margins. It may prove difficult to distinguish between these two causes, but their effects on biostratigraphic correlation and paleoecological interpretation may be sig 50 nificant. Steineclc (l971a), for instance, noted the ab sence of species of Morozovella, notably M. aragonensis. from Middle Eocene sediments in California, and postulated a period of climatic cooling whose onset coincided with the Early/Middle Eocene boundary. This species has been recog nized in Middle Eocene assemblages from the Northern Chan nel Islands (Weaver and Doerner, 1969; R» Morin, personal communication), which appear to represent an offshore facies with more completely developed faunas. Early Miocene Globigerinatella insueta Partial Range Zone Author: Cushman and Stainforth (19^5)* See also Bolli (1966a). Definition: The base of this zone is placed im mediately above the extinction of Catapsydrax dissimilis s.I.,1 and the top just below the earliest appearance of Praeorbulina glomerosa s.l. Discussion: Catapsydrax dissimilis, including the subspecies C. dissimilis ciperoensis, is a solution- resistant form which appears to be particularly widespread As used here and in following discussions, the term sensu stricto (s.s.) restricts discussion to the nominate subspecies (e.g., jC. dissimilis dissimilis). The term sensu lato (s.l.) is employed to designate all of the sub species collectively. 51 in tropical and subtropical assemblages. Most other zonations have recognized the stratigraphic usefulness of its extinction, and that usage is retained here. The upper limit of the zone was not observed at any of the sites examined here, and it has not been possible to verify whether the initial appearance of P. glomerosa can be recognized in deep-sea sediments. Jenkins and Orr (l971» 1972), however, were able to recognize this horizon although the species of Orbulina derived from P. glomerosa (Blow, 1956) appear to dissolve readily (Jenkins and Orr, 1971; Fleisher, 197^a) . Globigerinatella insueta, the nominate species of this zone, is only moderately resistant to solution but is present sporadically in the G. insueta Zone at Sites 219 and 237* The Globigerina venezuelana Zone of Jenkins and Orr (1972) is exactly equivalent to the Globigerinatella insueta Zone as used here. This zone corresponds to Zone N.7 and the early portion of N.8 of Blow (1969)* The upper limit of N.7 was placed just below the evolutionary appearance of Globi- gerinoides sicanus, and this usage has been widely fol lowed. Bronnimann and Resig (1971), however, observed the overlap in ranges of Catapsydrax spp. (including C_, dis similis . £. unicavus, and C. stainforthi) with G. sicanus and Praeorbulina glomerosa. The last of these is present only in a single sample very near the top of the first core 52 i^ure .5* Correlation of selected 1 Miocene zonation srstcr.is rly K E Y S PE C IE S Fleisher (this report) Blow (1 9 6 9 ) Berggren (1 9 72 a) Bolli (1 9 66 a) Jen kins and O rr (1 9 7 2 ) Postum a (1 9 7 1 ) Raju (1 9 7 0 , 1 9 7 1 ) o I 0| i : G lobigerinatella insueta Zone Catapsydrax dissim ilis Zo n e “ T u rb o ro tah a " kugleri Zo n e G lo b oquadrina binaiensis Z one N.4 Praeorbul/na glom erosa Zone , G lobigerinatella insueta Zone G lo b o ro ta lia ^ fohsi Zone G lobigerina veneauelana Zone G lobigerinatella insueta Zone Catapsydrax s ta in lo rth i Zone G /obigerinita dissimilis Zone Catapsydrax dissim ilis Zone G lobigerinoides' trilobus Zone G lob o ro ta lia kugleri Zone G loborotalia kugleri Zone G loboro talia kugleri Zone G lobigenna ciperoensis Zone G lobigenna angulisu tural/s Zone G lob/gerina angulisu turalis Zone G lobigerinoides trilobus Assemblage G lo b o ro talia kugleri - G lobigerinoides p rim ordius Zone ? ? ? G /obigerina angulisuturahs Zone 5h Oligocene Early Miocene recovered following: a long drilled interval; it is probably best explained by downhole contamination (Fleisher, 197^) • The extensive overlap of Catapsydrax spp. and G. sicanus. however, suggests that the initial appearance of the latter is not as reliable a datum as Blow (1969) assumed. In addition, Bronnimann and Resig (l97l) recognized a number of species very similar in form to G. sicanus. including G. praesicanus and G. praeimmaturus. with somewhat dif ferent ranges. The similarity of these forms makes the N.7/n*8 boundary very difficult to recognize. Occurrence: Site 219i Sample 219-13-2, 46—48 cm to Sample 219—l4—CC. The two isolated occurrences of C. dis— similis ciperoensis in Core 14 are probably reworked. Site 237: Sample 237-19-1, 79-81 cm. Catapsydrax dissimilis Partial Range Zone Author: Jenkins and Orr (1972), name corrected. Definition: The base of this zone is placed directly above the highest occurrence of r t Turborot alia” kugleri. and the top of the zone at the highest occurrence of Catapsydrax dissimilis s.l. Discussion: As defined, this zone correlates directly with N.5-N.6 of Blow (1969) and with the JC. dis similis and C. stainforthi Zones of Bolli (1966a). Both of these authors drew the boundary between their pairs of zones at the initial appearance of Globigerinatella in- 55 sueta, an horizon which seems unreliable in the deep sea because of the relative solubility of this species (see above). It may prove desirable to change the zonal name so as to avoid confusion with Bolli1s more restricted zone, but because of the limited expression of the (3. dissimilis Zone at Site 237 this step has not been taken. The most distinctive characterization of this zone is the overlap of species of Globigerinoides. particularly G. altiaperturus, with C. dissimilis s.l. in the absence of ”T." kugleri. This last species has been widely re ported, and its extinction appears to be a reasonably isochronous event. Postuma (l97l) chose to recognize in this interval a Globigerinoides trilobus Zone based on the overlap of C_. dissimilis and G. trilobus; the base of this zone appears to be somewhat older than the base of the <3. dissimilis Zone. Postuma made no distinction, however, be tween G. trilobus and G. quadrilobatus, a taxonomic separation recognized here, and in any case the horizon at which either became distinct from the ancestral G. primor- dius is difficult to determine with precision (Scott, 1970, 1971). Occurrence: Site 237? Sample 237-19-2, 79-81 cm to Sample 237—19—CC. 36 "Turboro tali a1 1 kugleri Total Range Zone Author: Bolli (1957b), name corrected. Definition: This zone is defined by the total range of "Turboro talia1 1 kugleri . Discussion: As noted above, most authors have recognized the boundary as drawn at the top of this zone. Two basic alternatives, however, have typically been fol lowed in drawing the base of the zone that occupies this stratigraphic position. Bolli (l957b, 1966a), Jenkins and Orr (1972), and Postuma (l97l)» among others, have used the zone concept employed here, although the differentia tion of "T." pseudokugleri and "T." mendacis from "T." kugleri has left the base of this zone slightly higher than originally drawn. Banner and Blow (1965a)> and subsequently Blow (1969)* chose to place the base of their Zone N.4 at the initial appearance of Globigerinoides primordius. This species was thought to evolve from Globigerina praebul- loides occlusa at an horizon within Bollifs Globorotalia kugleri Zone, and to give rise subsequently to all other Neogene species of Globigerinoides. This “Globigerinoides Datum" (Bandy, 1964), " one of the most important events in the evolutionary history of the Cainozoic Globigerina- cea," (Blow, 1969, p* 223) was recognized very near the base of the lectostratotype Aquitanian section and thus of the Miocene. The recognition of Zone N.4 provided not 57 only an easily defined and differentiated zone, but also a zone boundary that corresponds with a major epoch boundary. More recent investigations, however, suggest that this interpretation cannot be maintained. The base of the Aquitanian lectostratotype rests unconformably upon under lying rocks (Anglada, 1971)» and Globigerinoides primordius has been observed in sediments stratigraphically below the level of the stratotype. Scott (1972) examined specimens of G. primordius from one such locality (Escornebeou, France) where this species is found in conjunction with miogypsinids older than those at the stratotype. Bio- \ metric analysis of the Escornebeou planktonic specimens suggested that they are more primitive than those from the base of the stratotype section, and Scott concluded that they were indeed older. Additional evidence concerning the age of the “Globigerinoides Datum"has been derived from studies of other geographic regions as well. Sieglie (1973) found specimens of G. primordius in association with faunas attributable to the Globigerina ciperoensis Zone of Bolli (i.e., prior to the initial appearance of , r T. " kugleri) in mid-Tertiary strata in Puerto Rico. In deep-sea deposits, Poag (1972) reported G. primordius from Upper Oligocene horizons at Site 98 (western North Atlantic), below the earliest appearance of "T," kugleri. A similar strati graphic relationship was noted at Site 159 in the equa 38 torial Pacific (Kaneps, 1973)* At Site 237* the initial appearances of "T.” kugleri and G. primordius occur in the same sample (237-21—2, 79—81 cm). Because "T. 1 1 mendacis and "T." pseudokugleri. both of which evolved earlier than "T, 1 1 kugleri (Blow, 1969) » range slightly lower, it is clear that the joint appearance does not result from an unconformity. In view of these occurrences, it must be concluded that the initial appearance of Globigerinoides primordius is not only older than the Oligocene—Miocene boundary, but is sufficiently heterochronous to preclude its use as a reliable zone boundary. As a result, there appears to be no conclusive way to recognize the Oligocene—Miocene boundary on the basis of planktonic foraminifera. Bolli (l957h) tentatively placed this boundary within his Globorotalia kugleri Zone; later (1966a) he assigned this zone entirely to the Oligocene. In the absence of conclusive evidence, the precedent of Jenkins and Orr (1972) has been arbitrarily followed, and the epoch boundary is placed at the base of the "Turborotalia” kugleri Zone. Occurrence: Site 237l Sample 237—20—1, 79—81 cm to Sample 237-21-2, 79-81 cm. 59 Oligocene The Oligocene is poorly developed at the three sites discussed here, as well as at other sites in the Indian and Pacific Oceans (Heiraan e_t al, , 197^» McGowran, 197^> Fleisher, 197^a; Simpson e_t al, , 197^5 Kennett e_t al,, 1972), Unconformities representing much of Oligocene time have been very widely reported from DSDP studies, and in many cases where Oligocene sediment has been preserved, carbonate dissolution has been intense, A detailed examination of Oligocene hiatuses is be yond the scope of this report. Most of the speculation regarding the cause of this widespread unconformity has supported the conclusion of Kennett ejt al. (1972) relating this feature to erosion by deep currents associated with the early northward extension of Antarctic bottom water (Pimm, 197^5 Leclaire, 197^5 Schlich, 197^> Vincent, 197^0* It should be noted, however, that Rona (1973) has argued that such an explanation cannot account for the geographic extent of the reported hiatuses, and that Kent (197^) has suggested the influences of terrestrial processes (sedi ment supply) as an additional factor. Globoquadrina binaiensis Partial Range Zone Author: Here proposed. Type Section: DSDP Site 237, 07°0^.99'S, 58° 07.^8, E. 60 Definition: The base of this zone is placed im mediately above the extinction of "Turborotalia” opima opima. and the top is placed at the initial appearance of "T.” kugleri. Discussion: Xn its definition, this zone is identi cal with the Globigerina ciperoensis ciperoensis Zone of Bolli (1966a) and the Globigerina angulisuturalis Zone of Jenkins and Orr (1972). These species are very rare to absent, however, at all three sites, and this zone name has been proposed as a replacement on that account. The Globoquadrina binaiensis Zone is, technically, an interval—zone in the sense recognized by the Inter national Subcommission on Stratigraphic Classification (1972). Its typical fauna, nonetheless, can be loosely characterized. Globoquadrina binaiensis evolved just above (Blow, 1969) 9 or possibly slightly below, the base of this zone, and G. sellii became extinct near or just above the top. Xn addition, Neogloboquadrina siakensis evolved in the Late Oligocene and extends throughout this zone. The concurrence of these three species, therefore, is typical of, but not conclusive or necessary for, the G. binaiensis Zone. The nominate species may be only sporadically pre sent (as at Site 220), or may be absent altogether (Jenkins and Orr, 1972; Kaneps, 1973)* In these circum stances, the zone may be conclusively recognizable only within a stratigraphic succession. 61 6, Correlation of selected Oligocene zonation systems. H a n tk e n m a T u r b o r o ta h (C .) in f la ta a c e rro a z u le n s is s.l. C a ssig e n n e fla c h ip o le n s is KEY S P E C IE S P s e u d o h a s tig e n n a b a rb a d o e n $ i$ " T u r b o r o ta /ia " a m p fia p e rtu ra G lo b ig e rin a a n g u h s u tu r a l is G lo b o q u a d r in a s e lln C h tlo g u e m b e lin a c u b e n s is " T u r b o r o t a lia " o p im a s.s. G lo b o q u a o “ T u r b i rm a b in a ie n s is ir o t a h a " k u g le r i ? ? o § ! 3 S. o 3 1 & it r> r j * £ ? a o i l I i ra 0 a 5 3 3 « £ 2. 5 * S T s c u 5 U 3 ^ 5 c n £ j § « 2 < 1 ft 0 c % 3 % ? S i l l ™ I I s S L 2 ? Cl ! & 5 o 3 ^ c a, N Q. O 3. Zi 3 0 > O i c ^ 1 1 3 S N O 0 a > n £• *8 5T 0 ^ *0 05 *0 •sj z “ *0 to *0 N) O *0 N J y .v 2 \3 -V . NJ ^ .£ > □3 — T O o ^ J 5 SJ ^ ^ a; « 1 0 ^ " ffi 5 9 c N O o- o S j o ? S. o 5 £ j j ? N 3 5 2 . t5 - 9 « C? ; § H s 2 ; | £ 3 £ j sr 3 5 S * §■ 0 Sj V 3 tJ 5 Q •t c b Jt 1 s Ci S ’ H 1 £ 3 3 3 S t 2' 1 cs 3 | 3 tS' N ? c ^ -t) f 5 ’ <5 0 ^ 3* > O N ® 0 C D 3 > C 0 ) 00 0 C O Ci Ci 13 5 5 ? £ ° & * 1 o 3 2 □ Q. J n 2 S ° a. ? « i s - 5 5 5 3 o N : r C J - § * 5 c g n 9 1 ° 3 tQ 3 c ^ 3 N C r O 2 o Ci 5 . 0 3 Cr £ 0 N O 0 Q ) o £' a . tQ 0 S I I 3 5 * C 3 ! i « ? C Q 0 5 o N 2 O to S to — 'si Q J Q. O G lo b o r o t a lia c e r r o a z u /e n s is Z o n e O i 3 Ci N | . | - X tS c g 5 U 1 ^ N ^ §■ 9 t £ • n C 2. ! s « f C Q 0 ? ? N 2 O 5 U cI 2 TJ 0 3 to sj S Q 3 0 N 9 ^ C % § 9 c 0 J £ 'i 2 I o c i 1 a! 9 3 o 1 ^ o 9} 8- : & 3 - « c I " ^5 N 5 | O § g | « 2 I 2 j 1 9 N 8- S. 0 ^ 5 " 3 ‘O '-C c S 2 G l o b o r o t a lia k u g le r i G lo b ig e rin o id e s p r im o r d iu s Zone ? ? ? G lo b ig e r in a a n g u J is u tu ia h s Zone CD O J -* c CD L ate E o c e n e O h q o co n u E a rly M io c e n e This zone is equivalent to most of Blow's P.22, the top of which (evolution of Globigerinoides primordius) is heterochronous. It falls within the upper portion of the Globigerina angulisuturalis Zone of Postuma (l97l) and also within the upper section of the Globigerina ampli- apertura Zone of Raju (l97l)« Occurrence: Site 220: Sample 220-6-1, 70-72 cm to Sample 220-9-4, 70-72 cm. It is not clear that the top of this zone was re covered at this site. Site 237: Sample 237-21-3, 79-81 cm to Sample 237-22-3, 79-81 cm. "Turborotalia” opima opima Total Range Zone Author: Bolli (1957b). Definition: This zone is delimited by the initial appearance and extinction of “Turborotalia" opima opima. Discussion: "T. 1 1 opima opima is a widely distri buted and strongly solution-resistant species, and the recognition of this zone is relatively straightforward even within strongly dissolved sequences (e.g., Site 220). Blow's (1969) Zone P.21 corresponds to part of the "T. " opima opima Zone, but its base — the initial appear ance of Globigerina angulisuturalis--is unrecognizable at any of these sites. Postuma's (l97l) G. angulisuturalis 64 Zone includes the "T#" opima opima Zone at its base, and the extinction of “Turborotalia" ampliapertura. the bound ary between the G. angulisuturalis and G. ampliapertura Zones of Raju (l970)> falls within this interval. Jenkins and Orr (1972) recognized two zones within this interval, an upper Globorotalia opima Zone and a lower Chiloguembelina cubensis Zone, separated by the horizon of extinction of the latter species. Although the lower por tion of the "T." opima opima Zone does not appear to be represented in samples from these three sites, C. cubensis ranges above "T.” opima opima at both Sites 220 and 237* The subdivision recognized by these authors, therefore, cannot be applied here. Indeed, the citation by Blow (1969) of Chiloguembefina cf. CJ. cubensis as high as P.22 (early "T. 1 1 kugleri Zone of this report) suggests that the stratigraphic relationship reported by Jenkins and Orr may be of local significance only. Occurrence: Site 220: Sample 220-9-CC to Sample 220-10-CC. Site 237s Sample 237-22—CC. An unconformity at this site between Cores 22 and 23 juxtaposes this sample over Upper Eocene sediments. "Turborotalia1 1 ampliapertura Partial Range Zone Author: Bolli (1937b), name corrected. Definition: The base of this zone is placed im— 63 mediately above the highest occurrence of Pseudohastigerina barbadoensis. and the top is marked by the initial ap pearance of "T." opima opima. Discussion: The horizon marking the top of this zone has been discussed above. Blow (1969) encountered considerable difficulty in distinguishing "T." opima opima from "T." opima nana, and concluded that the taxonomic im precision involved precludes the use of this transition for biostratigraphic purposes. This conclusion cannot be evaluated on the basis of material examined here; no horizons containing phyletically primitive populations of "T," opima opima were recovered. This horizon has been widely recognized, however (Bolli, 1966a; Jenkins and Orr, 1972; Postuma, 1971; Kaneps, 1973)* and its use is provi sionally accepted here. Sediments representing this zone were not recovered in the holes studied in this report. The stratigraphic value of the extinction of Pseudohastigerina barbadoensis was questioned by Blow (l970a), who accordingly combined his zones P.19 and P.20. Taking the evolutionary appearance of Globoquadrina sellii in the Early Oligocene to be a "reasonably satisfactory isochronous surface for correlative purposes" (p. 265)» he noted fluctuations in the age of the P. barbadoensis ex tinction. In the Atlantic-Caribbean region there is little or no overlap of these two species; in some cases, P. barbadoensis disappeared locally before the appearance 66 of G. sellii. Considerable overlap, however, was noted in Indo-Pacific sections, where P. barbadoensis appears to have survived somewhat longer in tropical and subtropical latitudes. Provincial variations in tbe range of Pseudo- hastigerina spp, have also been noted by Berggren (1969a), Berggren ejt al. (1967), and Cordey e_t ad. (1970) , but the provinciality and taxonomy of this group remains poorly understood. It appears from these data that the P. barbadoensis extinction horizon is of limited biostratigraphic useful ness. It is distinctly heterochronous in the Atlantic- Caribbean —Mediterranean province, where the "T." ampli apertura and underlying Cassigerinella chipolensis-P. barbadoensis Zones probably cannot be consistently dif ferentiated (Beckmann ejt al. . 1969)* This horizon appears to be reasonably isochronous, however, in the tropical Indo-Pacific, within the limits of biostratigraphic pre cision. As P. barbadoensis is apparently resistant to test dissolution, the usage of Jenkins and Orr (1972) is followed here. Occurrence: Sediments representing this zone were not recovered at the sites studied in this report. Cassigerinella chipolensis — Pseudohastigerina barbadoen sis Partial Range Zone Author: Bolli (1966a), name corrected. 67 Definition: The base of this zone is placed im mediately above the extinction of the Turborotalia cerro- azulensis complex as recognized by Toumarkine and Bolli (1970)* The top of the zone is placed at the extinction of Pseudohastigerina barbadoensis . Discussion: There is considerable confusion with respect to the manner in which this zone has been defined. Bolli (1966a) recognized the base at the initial appearance of Cassigerinella chipolensis. but the top of the underly ing Globorotalia cerroazulensis Zone was placed at "the last occurrence of [thej zonal marker" (p. 15)• This situation is tolerable only if the two events fall at the same horizon; Blow (1969)* however, noted that they do not. If Bolli1 s concept of CJ. chipolensis included £. winniana (Cordey, 1968; Steineck and Darrell, 197l)» the overlap of these two zones is considerable; if not, an unzoned strati- graphic gap separates the two. £. chipolensis is relative ly rare in Middle Tertiary sediments in the western Indian Ocean and appears to be strongly susceptible to dissolu tion. The decision has been made here to recognize the base of this zone at the extinction of Turborotalia cerro azulensis s.l. The concept of this species employed here is nearly that of Toumarkine and Bolli (1970), and in cludes the subspecies T. cerroazulensis s.s., T. cerro azulensis cocoaensis. and T . cerroazulensis cunialensis. 68 The extinction of T, pomeroli occurs at or slightly below this horizon (Toumarkine and Bolli, 1970; Fleisher, 1974a.)* as does the "Hantkenina (extinction) Datum" of Berggren (l971a, 1972a), At the three sites studied here, these events are essentially synchronous, although on the Ninety- east Ridge (McGowran, 1974) "the Hantkenina extinction oc curs somewhat lower. Blow (1969) recognized a somewhat different set of zones spanning this interval. His P,19» equivalent to the upper part of the C. chipolensis-P, barbadoensis Zone, is characterized by the overlap of Globoquadrina sellii and P, barbadoensis. The underlying Zone P,l8 comprises popula tions containing Globoquadrina tapuriensis prior to the evolution of its descendent, G, sellii. Thus the base of Blow's Oligocene zonal sequence is marked by the initial appearance of G. tapuriensis, a level he placed somewhat higher than the Turborotalia and Hantkenina extinctions discussed above. Whether a zone equivalent to P.19 can be consistent ly recognized in deep-sea environments is not clear, Jen kins and Orr (1972) were unable to do so in the eastern Pacific, but McGowran (1974) observed the base of G. sellii at an appropriate level at Site 214, G. sellii is rather consistently present at Site 237» less so at Site 220, and absent at Site 219, This absence, however, may not reflect solution—susceptibility if the sediments re 69 covered in Cores 219-15 and 219-16 are equivalent only to P.18 rather than P.18-P.19. Blow (1969) concluded that the base of his Zone P. 18 fell somewhat above the top of Bolli*s Globorotalia cerro azulensis Zone. This interpretation has been generally followed (Raju, 1971; Postuma, 197l)• At least within the Indian Ocean, however, the two levels may be essentially equivalent. At Site 219, G> tapuriensis is sporadically present, but rare, in Cores 15 and 16; its lowest appear ance is only very slightly higher than the extinction of T. cerroazulensis. At Site 2l4 the two events appear to fall within the same sample near the base of Core 214—27 (McGowran, 1974)• For the purposes of this study, there fore, the £. chipolensis—P. barbadoensis Zone is taken as a close equivalent of Blow's P.18-P.19. Raju (1971) recognized two units— his Globigerina sastrii and G. gortanii Zones— which he correlated with the C. chipolensis—P. barbadoensis Zone of Bolli (1966a)* As discussed below (see SYSTEMATICS), G. sastrii appears to represent a variant of Globoquadrina sellii, and the ranges of the two are the same in the Cauvery basin of south eastern India. Jenkins and Orr (1972) drew the base of their P. barbadoensis Zone at the extinction of Globorotalia in— solita; T. cerroazulensis s.l. is absent from the restrict ed Late Eocene faunas at Site 77* Correlations between the 70 tropical Indian Ocean, where Globorotalia (probably = Tenuitella) insolita is absent, and the eastern equatorial Pacific cannot be made with confidence at present. Occurrence: Site 219s Sample 219-15-lj 51-53 to Sample 219-16-6, 51-53 cm. The specimens of T* cerroazulensis s.l. and T. pomeroli in Sample 219-16-4, 52-5** cm> are probably re worked. Late Eocene Turborotalia cerroazulensis Partial Range Zone Author: Bolli (1957 c), name corrected. Definition: This zone includes the interval between the highest occurrence of Globigerinatheka semiinvoluta and the highest occurrence of Turborotalia cerroazulensis s.l. Discussion: This zone has been very widely recog nized, and little discussion of its limits is necessary. Both T. cerroazulensis and G. semiinvoluta are widely dis tributed and morphologically distinctive, and their recog nition poses no serious problems. This interval is easily characterized in deep-sea sediments by the concurrence of T. cerroazulensis s.l., T . pomeroli. and Subbotina angi- poroides in the absence of G. semiinvoluta. Blow (1969) erected his Zone P.l6 to represent the interval containing Hantkenina (Cribrohantkenina) inflata; 71 the T. cerroazulensis Zone thus corresponds to P. 17 and part of P. 16, as H. (£. ) inf lata was reported to overlap G. semiinvoluta. P.l6 cannot be recognized in the deep ocean, however, as H. (C.) inflata appears to be highly susceptible to dissolution. Fleisher (l97^a)recognized an unconformity at Site 219 near the base of Core 17 be cause Zone P.16 appeared to be absent. The dissolution of the index species for this zone is a more likely interpre tation. Occurrence: Site 219: Sample 219-16-CC to Sample 219-17-4, 51-53 cm. Site 237: Sample 237-23-1, 79-81 cm to Sample 237-23-5, 79-81 cm. Globigerinatheka semiinvoluta Partial Range Zone Author: Bolli (1957c), name corrected. Definition: The base of this zone is placed im mediately above the highest occurrence of Truncorotaloides pseudodubius, and the top at the extinction of Globigerina theka semiinvoluta. Discussion: This zone represents very nearly the total range of the nominate species. Bolli (l957c, 1966a) and Postuma (l97l) placed the initial appearance of G. semiinvoluta and the highest occurrence of T. pseudodubius at the same horizon. Blow (1969), however, recognized a 72 T U . : Co. 1; .on of selected Late ;onation svs ':o ccnc / 3 Truncorotaloides pseudodubius G lobigerinatheka sem iinvoluta J H an tken in a (C.) in f lata H a n tk en in a (H .) alabamensis Turbo ro talia cerroazulensis s.l. Pseudohastigerina barbadoensis N C r o . o S 3 - -» O • C l 3 a g Q) ri O N 0 X *8 C D a N 0 O 5 D f t ) h Q j n f D O Q ) & v > t o M iddle Eocene Late Eocene 5 S ' a ? t S 1 Oligocene slight overlap of the two species, and this co-occurrence is observed at Site 219* Of the two species, T. pseudo- dubius is used here (following Blow, 1969) to delimit the zone because of its widespread distribution and its pre sence even in intensely dissolved faunas. G. semiinvoluta occurs sporadically throughout its range, and may prove un reliable in some deep-sea assemblages. G. tropicalis, how ever, ranges throughout this interval and becomes extinct at or slightly above (Bolli, 1972) the top of this zone. The occurrence together of these species, therefore, or the presence of G. tropicalis, in the absence of T. pseudo- dub ius , is indicative of but not quite conclusive for this zone • Occurrence: Site 219: Sample 219-17-5, 51-53 cm to Sample 219-18-2, 55-57 cm. Site 237: Sample 237-23-6, 79-81 cm to Sample 237-24-3, 79-81 cm. Early and Middle Eocene Truncorotaloides pseudodubius Partial Range Zone Author: Bolli (1957c), name corrected. Definition: This zone is defined to include the interval between the extinction at its base of Orbuli- noides beckmanni and the extinction of T. pseudodubius. Discussion: The T. pseudodubius Zone has been very 75 r c ■orrcxaiion ox scloctt [ladle Socene zonation • . .-i ..arly anc,. slens„ K E Y S P E C IE S F leish er (th is re p o rt) B lo w (1 9 6 9 ) Berggren (1 9 7 2 a ) Boll i (1 9 6 6 a . 1 9 7 2 ) P ostum a (1 9 7 1 ) Raju (1 9 7 0 , 1 9 7 1 ) G lo b ig e rin a th e k a s e m iin v o lu ta Z o n e T ru n c o ro ta lo id e s p s eu d o d ubius Z o n e . o____ O rb u tin o id e s b e c k m a n n i Z o n e G lo b ig erin a th eka c u rry i — G lo b ig e rin a th e k a \ euganea Z o n e f M o ro z o v e lla c o ro n a ta — M o ro z o v e lla aragonensis Z o n e G lo b ig erin a th eka senni Z o n e / M o r o z o v e lla \ fo rm o sa — \_ M o ro z o v e lla aragonensis Z o n e P. 16 P. 15 P. 14 P. 1 3 P. 12 P .1 0 P.9 P. 8 G lo b ig e rin a th e k a s em iin vo lu ta Z one G lobigerapsis m exican a Z o n e G lobigerapsis m e x ic a n a Z o n e Tru n c o ro ta lo id es roh ri Z o n e T ru n c o ro taloides ro h n Z o n e T ru n c o ro ta lo id e s ro h ri Z o n e O rb u tin o id e s b e c k m a n n i Zo n e O rb u tin o id e s b e c k m a n n i Z o n e O rbutinoides b e c k m a n n i Zo n e G lo b o ro ta lia leh n eri Z o n e G lo b o ro ta lia leh n e ri Z o n e T ru n c o ro taloides topilensis Z o n e G lo b ig e rin a th e k a subcongtobata Z o n e H a n tk e n in a aragonensis Z o n e G lo b o ro ta lia p a lm e ra e Z o n e G lo b o ro ta lia aragonensis Z o n e G lobigerapsis k u g leri Z o n e G lo b o ro ta lia b u llb ro o k i Z o n e I G lo b o ro ta lia ^ fo rm o sa - G lo b o ro ta lia aragonensis Zone G lobigerapsis k u g le ri Z o n e H a n tk e n in a aragonensis Z o n e > (A ) G lo b o ro ta lia p a lm e ra e Z o n e G lo b o ro ta lia aragonensis Z o n e (A ) — G lo b ig erin a tu rg id a — G lo b ig erin a sen n i Z o n e ( s widely used in tropical and subtropical regions (see Krasheninnikov, 1969; Krasheninnikov and Ponikarov, 1965)♦ and requires little additional discussion here. The top of this zone marks the final appearance in low-latitude populations of the pseudospinose-walled forms (i.e., Truncorotaloides. Acarinina, and Morozovella)• Although Blow (1969) drew the Middle/Late Eocene boundary within this zone, most other workers (e.g., Berggren, 1972a) have included this interval entirely within the Middle Eocene. The latter convention has been followed here. Blow (1969) noted Berggren's (1969a) report of oc currences of Truncorotaloides and Acarinina with Late Eocene planktonic populations in high-latitude regions, and suggested caution in the use of his Zone P.l4. Berggren1s illustrations of T. pseudodubius. however, seem more to represent T. collacteus. In any case, this expanded range in temperate regions appears to be limited to the northern hemisphere. Berggren's citation of a Late Eocene extinc tion for Acarinina/Truncorotaloides in New Zealand was based on Jenkins's (1965a) placement of the T. p s eudo dub ius Zone in the Late Eocene. True extensions of these forms into generally recognized Late Eocene horizons have not been observed in either New Zealand (Jenkins, 1971; Srinivasan, 1968) or Australian strata (McGowran and Lindsay, 1969; Ludbrook and Lindsay, 1969)• The suggestion that "Trun corotaloides appears to have reacted as a cool—temperate 78 species in its later distribution • • •" (Berggren, 1969a, p. 139) may be valid only for the northern hemisphere. Occurrence: Site 219J Sample 219-18-3* 33-55 cm to Sample 219-19-5, 52-54 cm. Site 237: Sample 237-24-4, 79-81 cm to Sample 237—24—CC• The base of this zone was not recovered at either site • Orbulinoides beckmanni Total Range Zone Author: Bolli (l957c), name corrected. Definition: This zone is defined by the range of the nominate species. Discussion; This zone was not recovered at any of the low- to mid-latitude sites (i.e., Legs 23, 24, or 25) in the western Indian Ocean. McGowran (1974), however, reported samples from this zone on the Ninetyeast Ridge (Site 214) . The absence of (). beckmanni. therefore, does not seem to reflect test dissolution, but probably indi cates a short-term period of regional erosion or non deposition. Occurrence: Sediments representing this zone were not recovered at these three sites. 79 Globigerinatheka curryi — Globigerinatheka euganea Partial Range Zone Authors Here proposed* Definitions The base of this zone is placed im mediately above the highest occurrence of Morozovella aragonensis * The top is placed just below the evolution ary appearance of Orbulinoides beckmanni from its ancestor Globigerinatheka euganea. Type Sections DSDP Site 237, 07°04.99'S, 58°07.48'E Discussions This zone is equivalent to the Globorotalia lehneri Zone of Bolli (1966a) and Postuma (l97l), to P.l4 of Berggren (1971a), to the Truncorota loides topilensis Zone of Raju (1970), and to the Acarinina rotundimarginata Zone of Krasheninnikov (1965; fide Bolli, 1972)* With the possible exception of the last, these zones can be recognized within a stratigraphic sequence of deep-sea sediments because the species defining the upper and lower boundaries are both widespread and resistant to dissolution* It has proved very difficult, however, to character ize the faunas within this zone. Specimens of Morozovella lehneri. if this taxon is restricted to forms with dis tinctly elongate chambers similar to those of the holotype, occur only very rarely. Most of the forms referred to this species from deep-sea sediments should probably be placed in M. coronata (Fleisher, 197^a)• Only very rare 80 and questionable occurrences of T. topilensis were re covered from samples from the Sites 219 and 237* These species, accordingly, have not proved useful in recogniz ing deep-sea faunas of this age, Bolli (1972) discussed in detail the stratigraphic distribution of the various species of Globigerinatheka. G. curryi evolved, probably from G. subconglobata. some what below the extinction of M. aragonensis. Within the Globorotalia lehneri Zone Globigerinatheka curryi gave rise to G. euganea. and then became extinct prior to the evolution of Orbulinoides beckmanni. G. euganea survived into the 0. beckmanni Zone. On the basis of these ranges, the G. curryi-G. euganea Zone can be characterized by the presence of either or both of these forms in the absence of M. aragonensis and 0. beckmanni. All of these species are strongly resistant to dissolution, and the nominate taxa are tropical to temperate in distribution (Bolli, 1972). The zone can be readily recognized at Sites 219 and 237, and probably at Site 214 (McGowran, 1974)• Occurrence: Site 219s Sample 219—19—6, 51—53 cm* Site 237s Sample 237-25—1* 79—81 cm to Sample 237-27-1, 79-81 cm. The upper part of this zone was not recovered at this site. 81 Morozovella coronata - Morozovella aragonensis Concurrent Range Zone Author: Here proposed. Type Section: DSDP Site 237, 07°04.99*S, 38°07.^8,E Definition: The base of this zone is placed at the initial appearance of Morozovella coronata. and the top at the highest occurrence of Morozovella aragonensis. Discussion: This zone is characterized by the joint occurrence of Morozovella coronata and M« aragonensis. Both are widely distributed (M. coronata. it appears, is usually referred to M. spinulosa; see SYSTEMATICS, below), and both seem to be common in deep-sea sediments in the tropical Indian Ocean (Fleisher, 197^? McGowran, 197^+? Heiman et al. . 197^-» probably as M. spinulosa) . Thus this zone should be highly suitable for application to deep-sea sequences. The M. coronata — M. aragonensis Zone is equivalent to the interval represented by the Globigerinatheka sub— conglobata (=Globigerapsis kugleri) and Hantkenina (H.) aragonensis Zones of Bolli (1966a, 1972) and Raju (1970), and Zones P.11 and P.10 of Berggren (1972a). All but the upper boundary of this interval in these zonations is controlled by the presence of Hantkenina (H.) aragonensis. This species, the first of that genus to evolve, first appears at the base of the H. (H.) aragonensis Zone ("Hantkenina Datum” of Berggren, 1972a) and disappears at 82 the top* Most of the species of Hantkenina, including H. (H.) aragonensis and H. (H.) mexicana, are strongly susceptible to dissolution and are only occasionally found in deep-sea sediments. Fleisher (197^a) reported only rare, fragmented, and isolated occurrences of these forms at Sites 219 and 220; McGowran (197^0 > similarly, judged the Hantkenina Datum to be unreliable at Site 21^. In practice, H. (H.) aragonensis is a poor species to use for correlation in deep-sea sequences. There is good reason to believe that the initial appearance of M. coronata approximates the horizon of evolution of Hantkenina spp. Bolli (1957c) placed the first appearance of his Globorotalia spinulosa Cushman at the base of the H. (H.) aragonensis Zone, and Berggren (l971b, Fig. 2) concurred with this interpretation. This horizon, according to Berggren, approximates the level of extinc tion of Morozovella caucasica; McGowran (197^0 noted the extinction of M. caucasica and appearance of M. coronata at the same horizon at Site 214 (Fig. k). Finally, this close coincidence of events was noted at Site 220 (Fleisher, 197^a)» and as reported here, at Site 237* The near synchroneity of the base of the Hantkenina aragonensis and Morozovella coronata - M. aragonensis Zones thus seems to have been conclusively documented. 83 Occurrence: Site 219s Sample 219-19-CC to Sample 219-21-CC. The base of* this zone was not recovered at this site. Site 220: Sample 220-12-1, 135-137 cm to Sample 220-13-2, 70-72 cm. Contrary to the interpretation of Nigrini ejt al. (1974), there is no conclusive evidence of* overlap of the sections at Sites 219 and 220. This inter pretation illustrates the pitfalls in placing undue re liance on the first appearance of a sporadically occurring form, in this case Hantkenina (H.) aragonensis. Site 237s Sample 237—27—2, 84—86 cm to Sample 237-29-CC. Globigerinatheka senni Partial Range Zone Author: Here proposed. Type Section; Site 220, 06°30.97fN, 70°59.02»E Definition: The base of this zone is placed at the first appearance of Globigerinatheka senni. and the top is placed immediately below the initial appearance of Moro- zovella coronata. Discussion: The convention proposed by Berggren (1968, 1971a, 1972a) of drawing the Early/Middle Eocene boundary at the base of the Hantkenina (H.) aragonensis Zone or its equivalent has been followed here. The G. senni Zone, therefore, characterized by the presence of G. senni prior to the initial appearance of M. coronata. is 84 the highest biostratigraphic unit in the Early Eocene* Two other zones are commonly used to represent this interval* Bolli (l957c) proposed a zone based on the total range of Globorotalia palmerae (= Globanomalina palmerae in the generic terminology of this report). Berggren (1968) argued that G. palmerae was a benthic species more pro perly assigned to the genus Pararotalia. In view of the scarcity, or more often absence,of this species in plank— tonic faunas of late Early Eocene age, most workers have followed his suggestion. Recently, however, Schmidt and Raju (1973) have presented the results of detailed investigations of the morphology of well-preserved specimens of G. palmerae from southern India, one of the few places from which it has been reported* Their evidence strongly suggests a plank- tonic habit for this species, which they convincingly show ed to be a close relative of Globanomalina pseudoscitula. Nevertheless, the scarcity of this form and its virtual if not complete absence from deep-sea sediments preclude its use as a zone fossil in all but localized zonation systems. Berggren (1968) defined an Acarinina bullbrooki Zone, characterized by the presence of A. bull- brooki and M. aragonensis prior to the appearance of Hant kenina aragonensis. which he considered to correspond ap proximately to the G. palmerae Zone. Subsequently (l971a), concluding that A. bullbrooki was a junior synonym of A. 85 densa (= Globorotalia crassata densa Cushman), he renamed this zone the Acarinina densa Zone and assigned it a P. 9 designation. The taxonomic problems related to the recognition of A. bullbrooki have already been briefly discussed, and will receive additional treatment below (see SYSTEMATICS). At least three, and probably more, separate forms have been included in the concept of A. bullbrooki. a species name which, with A. densa (see Pessagno, 1961), appears to have been used for almost every late Early to Middle Eocene planoconical acarininid. It seems best to avoid the use of the A. bullbrooki Zone (P.9) until a careful study of these populations has been made. The base of the Globigerinatheka senni Zone is poorly defined at Site 220 because of discontinuous coring and poor recovery. Schmidt and Raju (1973) have suggested, on the basis of Bolli*s (1957c) data, that the initial ap pearance of G. senni approximates the horizon of evolution of Globanomalina palmerae. Stainforth ejt al. (in press), however, has recently reported a slightly earlier occur rence of G. senni. Occurrence: Site 220: Sample 220—13—3* 70—72 cm to Sample 220-15-CC. G. senni is present in Sample 220-16-2, 68-70 cm, but the fauna in this sample appears to be mixed. The sample follows a drilled interval; this occurrence of G. 86 senni probably results from downhole contamination. Site 237: Sample 237-30-1* 95-97 cm to Sample 237-32-CC. The base of the G. senni Zone was not re covered at this site. Morozovella formosa - Morozovella aragonensis Partial Range Zone Authors Modified from Bolli (1957a), name cor rected. Discussions Recovery was too poor, and the sampl ing interval too irregular, to attempt a detailed biostrati graphic analysis of the few samples from Cores 16 through 19 at Site 220. Nonetheless, some comments on their age assignment can be made. Pseudohastigerina wilcoxensis and Morozovella aragonensis are present throughout this interval, and these samples must therefore fall within the M. formosa or M. aragonensis Zones of Bolli (1966a). The boundary between these zones is indistinct, however, particularly in view of the poorly defined morphology and range of the two species (Globorotaloides turgidus and ?Subbotina taroubaen- sis) whose first appearances mark that boundary. As pro posed by Postuma (l97l)> therefore, these two zones have been combined. 87 Correlation of sclnc ted t i ■ly TIi< j c en< a 1 an1 ' .a O C O I I O oi'aniini 1 zonatIon systems AGE M. Y (Berggren, 1972a) Fleisher (this report) Blow (1 9 6 9 ) Berggren (1972a) Bolli (1966a, 1972) Jenkins & Orr (1 9 72 ) Postuma (1 9 71 ) Raju (1 9 70 , 1971) M iddle G l o b i g e n n a t e l la m s u e ta Zone Early C a t a p s y d r a x d / s s im t lis Zone " T u r b o r o t a h a " k u g l e r i Zone G l o b o q u a d r i n a b / n a ie n s / s Zone " T u r b o r o t a h a " o p i m a o p i m a Zone 30 Oligocene _ " T u r b o r o t a h a " a m p li a p e r t u r a Zone 35 — C a s s .g e r /n e lla c h t p o /e n s is P s e u d o h a s t ig e n n a b a r b a d o e n s is Zone Late 4Q _ _ Eocene T u r b o r o ta h a c e r r o a z u le n s is Zone G I o b ig e r i/ r a t h e k a s e m i i n v o lu t a Zone T r u n e o r o ta lo id e s p s e u d o d u b / u s Zone O r b u h n o /d e s b e c k m a n n i Zone M iddle Eocene G lo b i g e r i n a t h e k a c u r r y / G e u g a n e a Zone M o r o z o v e l l a c o r o n a t a - M . a r a g o n e n s is Zone Early G l o b ig e r in a t h e k a s e n n i Zone M o r o z o v e l l a f o r m o s a - M . a r a g o n e n s is Zone G l o b o r o t a l i a f o h s i s. I. "Z o n e s J P r a e o r b u l i n a U g lo m e r o s a Zone G l o b o r o ta h a f o h s i s.I. Zones G l o b o r o t a l i a f o h s i s . I. Zones G l o b ig e r in a t e ll a in s u e t a Zone G l o b i g e r i n a v e n e z u e la n a Zone G l o b / g e r i n a t e l l a in s u e t a Zone C a t a p s y d r a x s t a in f o r t h / Zone G l o b ig e n n o id e s t n / o b u s Assemblage C a t a p s y d r a x d i s s i m ih s Zone G l o b i g e r i m t a d is s im ih s Zone G lo b / g e n n o / d e s t r i lo b u s Zone G l o b o r o ta lia k u g l e r i Zone G l o b o r o ta h a k u g l e r i Zone G l o b o r o t a l i a k u g l e r i Zone G l o b i g e r i n a c ip e r o e n s is Zone G l o b i g e r i n a a n g u h s u t u r a h s Zone G l o b o r o t a l i a o p i m a Zone o p im a o p i m a Zone C h if o g u e m b e / in a c u b e n s is Zone P 20 G l o b i g e r i n a a m p li a p e r t u r a Zone G lo b i g e r i n a a m p li a p e r t u r a Zone C a s s ig e r in e lla c h ip o l e n s i s - H a s t i g e r in a m t c r a Zone P s e u d o h a s t ig e r m a b a r b a d o e n s is Zone P. 16 G l o b o r o t a l i a c e r r o a z u le n s is Zone G l o b o r o t a l i a i n s o f i t a Zone G lo b i g e r i n a t h e k a s e m i i n v o lu t a Zone T r u n c o r o t a l o i d e s r o h r i Zone O b e c k m a n n i Zone G l o b o r o t a l i a le h n e r i Zone G lo b i g e r i n a t h e k a s u b c o n g / o b a t a Zone H a n t k e n i n a a r a g o n e n s is Zone G l o b o r o ta h a p a lm e r a e Zone G l o b o r o t a l i a a r a g o n e n s is Zone G lo b i g e r i n a a n g u h s u t u r a h s Zone G l o b o r o ta h a k u g l e r i — G / o b ig e r m o id e s p n m o r d i u s Zone ? ? ? G l o b i g e r i n a a n g u h s u t u r a h s Zone G l o b i g e r i n a a m p li a p e r t u r a Zone G lo b i g e r i n a a m p li a p e r t u r a Zone G lo b i g e r i n a s a s t r ii Zone G l o b i g e r i n a g o r t a n i i Zone G l o b o r o t a l i a c e r r o a z u le n s is Zone G l o b o r o t a l i a c e r r o a z u le n s is Zone G lo b ig e r a p s is m e x ic a n a Zone G lo b ig e r a p s is m e x ic a n a Zone T r u n c o r o t a l o i d e s r o h r i Zone T r u n c o r o t a l o i d e s r o h r i Zone 0 . b e c k m a n n i Zone O. b e c k m a n m Zone G l o b o r o ta h a l e h n e r i Zone T r u n c o r o t a lo id e s t o p i/ e n s is Zone G lo b ig e r a p s is k u g l e r i Zone G lo b ig e r a p s is k u g l e r i Zone G l o b o r o ta h a b u l l b r o o k i Zone G l o b o r o t a l i a f o r m o s a G . a r a g o n e n s is Zone H . a r a g o n e n s is Zon ^ G l o b i g e r i n a t u r g i d a \ G . s e n n i Zone \ G . " p a l m e r a e Zoney G l o b o r o t a l i a a r a g o n e n s is Zone Figure 10, Correlation of sequences at Sites 219 , 220, and 2 37 w 11h proposed deep-sea zonation system, 00 ZONES SITE 219 SITE 220 SITE 237 1 3 - 2 - 1 4-CC 19-1 19-2 19-CC 20-1 "Tu rborotaha" kugleri 21-2 G/oboquadnna b/naiensis 6-1 9-4 22-3 9-CC 22-CC "Turborotaha" opima opima 10-CC ''Turborotaha" amp/iapcrtura 1 5-.1 Pseudoh as tigerina barbadoensis 1 6-6 16-CC Turborotaha 23-1 cerroazulensis 23-5 17-4 2 3 6 17-5 Glob igerin atheka semiinvoluta 24-3 1 8-3 T. pseudodubius 19-5 O. beckmanni G. curryi-euganea 19-6 19-CC 27-2 M. corona ta - M. aragonensis — - 21-CC 1 3-2 29-CC 1 3-3 G. senni 15-CC 16-2 M. formosa — M. aragonensis 91 SYSTEMATXCS Introduction The generic assignments utilized in this report for Cenozoic planktonic foraminiferal species differ consider ably, in many cases, from those usually encountered in the literature. This variance reflects a serious disagreement on both practical and philosophical bases with the classi fication systems most widely used for these forms and the considerations upon which these systems are based. The nature of this disagreement has been discussed in detail elsewhere (Fleisher, 197^)» and will only be summarized here. Two systems of planktonic foraminiferal classifica tion are currently in common use, those of Bolli et al. (1957) and, in particular, of Blow (Banner and Blow, 1959; Blow, 1969)# Both are based entirely upon characteristics of gross test morphology. The most important of these characteristics is the mode of coiling, but because the vast bulk of planktonic foraminiferal species are trocho— spiral a second-level criterion, the position and modifica tions of the aperture, effectively serves to distinguish the major genera. Thus, in these classification systems, 92 forms with, non-bullate umbilical apertures are assigned to Globigerina. species with bullate apertural modifications are placed in Globigerinita (Blow, 1969) or Catapsydrax (Bolli e_t al. , 1957) » and those with extraumbilical apertures in Globorotalia s.l. Other characteristics on which genera are recognized include such features as secondary apertures (Globigerinoides, Globigerinatheka) and chamber extensions (Bolliella) or tubulospines (Hant- kenina). These taxonomic classifications, then, depend upon the application of “rigid structural hierarchies” (Stein- eck, 1969) of morphologic characters which have been as signed importance largely on an a priori basis. In some respects this approach has distinct practical advantages, particularly in its ease of application. The purely morphological definition of genera means that if the criteria are well-defined and easily recognized, the as signment of species to generic categories is relatively simple. This apparent practicality would be particularly appealing to biostratigraphic specialists whose need for taxonomic nomenclature is limited largely to the necessity of designating particular species. In this line of reason ing, the species is the fundamental, if not sole unit of importance in biostratigraphic correlation. The choice of a generic name, then, is of significance only insofar as it influences species—level homonymy or provides mnemonic 93 assistance in recognizing broad morphotypes• If the as signment of species to genera is relatively simple, it is then of little consequence that it may be equally arbitrary and artificial. At this juncture fundamental questions about the nature and function of taxonomic systems need to be examined. What, in fact, is the purpose of a classifica tion system? Or, in turn, what sorts of criteria can be used as a basis on which to judge the "best1 1 system of classification? Much energy has been expended debating these considerations in Systematic Zoology during the last decade; one of the best treatments is that of Bock (1973)* Bock's conclusion is that two such fundamental criteria exist; others may either be reduced to one of these two, or are so vague that they cannot be used to evaluate the usefulness of taxonomic systems. One is practicality and prediction; that is, not only can the system accommodate already-recognized species, but it pro vides a satisfactory basis for incorporating newly- discovered forms. In this regard, the widely used nomen- clatural systems for planktonic foraminifera are eminently suitable; although new taxa may occasionally become neces sary to recognize newly-discovered morphotypes, most species named in the last fifteen years have been incor porated with little difficulty. The second criterion, however, is the extent to 9 h which, a given system "is the most accurate representation of* the phylogenetic history of organisms" (Bock, 1973* P* 379). In a fundamental sense, the hierarchic structure of Linnean taxonomy represents an attempt to reflect natural relationships. That these were not recognized to be evolutionary relationships until 1859 is not critical to the usefulness of that structure. Most of the controversy among biologists as to the best approach to classification appears to deal with attempts to find a methodology to satisfy this criterion for groups with a nonexistent or poor fossil record (Bock, 19695 Colless, 1967, 1969)* Among Cenozoic planktonic foraminifera, however, this limitation is much reduced in that an extensive fossil re cord with large populations is available for study. As a result, the broad outlines of planktonic foraminiferal evolution can be deduced and, particularly in the Neogene, many of the details recognized with reasonable reliability. Within limits, therefore, it is possible to apply the "evolutionary classification" of Mayr (1968), which "de limits taxa on the basis of two considerations— common ancestry and subsequent divergence, ^and vhosej method is to infer relationship on the basis of an a posteriori weighting of similarity" (p. 5^8). It is very much Mayr*s evolutionary classification approach that is advocated here. The objection raised here to the current planktonic foraminiferal classifications 93 is that they fail to reflect the evolutionary relation ships developed after intensive study of Cenozoic popula tions. McGowran (l97l) pointed out that ”the fact of evolution is invoked repeatedly in stating the need to use ’basic’ and ’less adaptive* characters” (p. 815) as the basis for classification. Blow’s (1969) classification, which many workers have followed, is unsatisfactory in this regard. Fleisher (l97^a)cited examples to support this contention and concluded that "his £b1ow*sJ system in no way intentionally reflects the evolutionary patterns he recognized” (p. 1009). It seems doubtful, indeed, whether any classifica tion system based on gross test morphology can reliably ex press these patterns. Gould (1970) has shown that overall form represents an interaction between selection and com petition on one hand and genetic inheritance on the other. Much valuable information concerning the evolution of a group of species can thus be obtained from a study of their functional morphology. The lack of detailed infor mation on the life habits of planktonic foraminifera has largely precluded all but the broadest application of this approach, although Scott (1973a* 1973h) attempted to ac count for the multiple and parallel evolution of keeled forms in different lineages of Early and Middle Miocene globorotaliids. Nevertheless, even the broad descriptive view of 96 Cenozoic planktonic foraminiferal populations (Cifelli, 1969) illustrates the importance of this approach to their classification. Two periods (Early Paleocene and Oligo— cene) dominated by relatively simple and generalized forms were followed by rapid radiation and diversification (Berggren, 1969b). The striking feature of these evolu tionary bursts is the recurrent development of similar morphotypes, in response to similar environmental pres sures (Frerichs, 197l) or as an adaptive strategy by similar but unrelated forms to occupy a particular niche. Gross test form, then, is an unfortunate choice as the basis for a classification because it has been particularly plastic in response to these pressures. The widely—used classification systems are all but incapable, as a result, of avoiding the erection or use of polyphyletic taxa— of satisfying, that is, Bock’s (1973) second criterion. An alternative approach (Parker, 1962, 19^7> Lipps, 1966) has involved the use of surface wall texture as a basis for classification. Lipps (1966) in particular has documented the reasons for considering this test feature to be phyletically conservative and advocated its emphasis in planktonic foraminiferal taxonomy. Xn general, his assessment of the stability of wall structure appears to be justified and his criteria have played an important role in the generic assignments made here. Nonetheless, Lipps' classification differs from Blow's (1969) largely in their 97 choice of differing definitive morphological criteria. The underlying taxonomic philosophy is much the same, and al though the Lipps classification may more nearly reflect evolutionary relationships because of the accuracy of his assumptions, it suffers from a similar structural in flexibility in its reliance on a single, or very few, morphologic features. Polyphyletic taxa remain a pos sibility whose exclusion is intended but which may not be recognized from morphologic characters alone. The wall textures of some of the Paleocene to Late Eocene globoro- taliform species here placed in Globanomalina (e.g., G. pseudomenardii. G. pseudoscitula; see Krasheninnikov and Hoskins, 1973, PI. 27, Figs. 1-3; Schmidt and Raju, 1973, PI. l) are strikingly similar to those of many modern species of Globorotalia. Currently accepted models of the broad evolutionary patterns of these two species groups (Berggren, 1968, 1971b; McGowran, 1968; Blow, 1969; Fleisher, 197^) strongly suggest that they are no more than distantly related. Morphologically, however, there appears to be no significant basis for distinguishing the two by means of either overall morphology or wall texture. Lipps (1966) does not, in fact, appear to have differentiated them at all. Xt is unlikely that any system of classification based entirely upon test features alone can reflect fully the complex interrelationships of Cenozoic planktonic 98 foraminiferal species* Turborotalia frontosa and T* pseudoampliapertura* for instance, are morphologically in distinguishable in terms of "generic-level” characters from contemporaneous species properly placed in Subbotina* but their evolutionary history indicates that this distinction should be made (Toumarkine and Bolli, 1971; Blow, 1969)* Within acknowledged genus groups in particular, morphol ogical criteria alone frequently do not distinguish im portant subgroups of related forms. Most specialists, for example, would agree that the Globorotalia fohsi and G. cultrata sublineages were completely independent after the late Early Miocene, but there is no purely morphological basis for separating them (Blow and Banner, 1 9 6 6 ; Olsson, 1972; Fleisher, 197^a). The sole basis of classification suitable for re flecting the biological and evolutionary relationships be tween planktonic foraminiferal species is the reconstructed phylogeny of these forms* The information upon which such a system could be based is available in part, particularly for Oligocene and Neogene populations, but few attempts to utilize this approach have been undertaken (Bandy e_t al. , 1967; Bandy, 19725 McGowran, 1968; Steineck, 1969, 1971b)* The proposal of a formal and comprehensive system at this time is not justified because a number of the lineages, particularly in the Paleocene and Eocene, are poorly known. There are no significant advantages, however, to 99 awaiting the solution of all major phyletic problems before this approach is applied to classification* Taxonomic systems should be regarded as evolving and testable scientific theories, and there is no inherent problem in modifying such a system as new information becomes avail able * Where published information is sufficiently de tailed and informative the lineage concept has been ap plied, and phylogeny has been assigned greater weight than arbitrary limits based on gross test morphology. In some instances groups of species can be recognized which share a number of morphologic traits and appear to be closely related; these include such groups as "Globigerina" and Tenuitella* Although detailed lineages cannot now be con structed for these assemblages, each one appears to have undergone an evolutionary history distinct from other genera. A few species groups of Paleogene age present es pecially troublesome problems to the application of evolutionary classification. These include most notably the species here placed in Acarinina, Morozovella, and Truncorotaloides. Several phylogenetic reconstructions have been advanced for these forms (Berggren, 1968, 1971h; McGowran, 1968; Steineck, 1971h), but none of these is en tirely convincing. A recent report (Samuel, 1972) ap pears to represent more accurately the evolutionary rela— 100 tionships of some of these species, but several of the lineages have not yet been evaluated and this phylogenetic reconstruction has not been incorporated into the taxonomic system employed here* The genera cited above have been treated in this report largely as form genera pending future interpretations of phylogeny, but the generic name applied to each is that which best appears to reflect the evolutionary affinities insofar as they are known. Comments on Surface Wall Texture Careful examinations of wall texture and the inter pretations made from them have provided much of the basis for recognizing and evaluating lineages, and thus for the generic assignments made below. The consistency of re sults obtained through this approach with the broadly ac cepted published phylogenies lends weight to Lipps* (l966) arguments in support of the evolutionary stability of wall surface texture. Fleisher (l97^a) recognized five basic wall types, and the differentiation of a sixth appears to be warranted. These include: 1. The spinose wall (e.g., Globigerina. Globi- gerinella). The surface of the wall is fundamentally flat, but it is modified by cylindrical pores and by acicular spines. In tests from sea-floor sediments, these spines are represented by short spine bases. The density of both pores and spines may be high, but there is no consistent or 101 regular pattern evident in their location. Distinct pore pits and interpore ridges are absent. Cancellate spinose wall (e.g., Globigerinoides. "Globigerina”). Pores are located at the center of well- developed depressions, or pore pits, separated by rela tively narrow ridges. The pore pits may be flat-bottomed or funnel-shaped, but do not simply reflect the slight widening of the pore near the wall surface. The visual impression typically created by this wall type is of a regular, reticulate network of intersecting ridges. Acicular spines are localized at ridge intersections. 3* Cancellate nonspinose wall (e.g., Turborotalia. Globoquadrina). This wall type is essentially similar to the cancellate spinose wall, except that the spines are absent. It may be that studies based on sections instead of surface examination will indicate greater differences; at present, however, it appears that the cancellate spinose wall arose only once (probably with "Globigerina1 *) from cancellate nonspinose forms, apparently during the Oligocene. The distinction proposed by Steineck (1971b) between "cancellate1 1 (e.g., Subbotina) and "pitted" (Turborotalia) appears to be one of degree rather than nature, and it is not adopted here. Finely perforate wall (Globorotalia. probably Globanomalina). Cylindrical pores are distributed evenly but without evident pattern over a smooth, spineless sur- 102 face. In reflected light, the perforations appear to be very small and are frequently difficult to observe, 5, Pseudospinose wall (e,g,, Acarinina, Morozo- vella), The wall appears to be fundamentally flat in that the pores are cylindrical and without pore pits. The sur face, however, is characterized by short, stubby projec tions (pseudospines) which may be distributed over the whole test (Acarinina) except where obscured by secondary deposits, or concentrated on the umbilical shoulders, the spiral and dorsal intercameral sutures, or along the peri phery (as, typically, in Morozovella), These pseudospines appear to be structurally and probably funtionally dif ferent from the spines of Globigerina« and the two wall types should not be confused, 6, Microperforate wall (Globigerinita, Tenuitella), The wall is characterized by extremely small (approxi mately 0,6 /*> perforations irregularly distributed on a smooth surface. Small pustules or microcrystallites are commonly developed on the wall and may obscure or cover the perforations. In reflected light these species appear to be imperforate, although the roughness of the wall (if sufficient microcrystallinites develop) may falsely suggest the presence of small pores. Typically, the test wall is very thin and seemingly fragile; in well-preserved speci mens, it is commonly translucent. 103 Species Descriptions GENUS Acarinina Subbotina, 1953 Type Species: Acarinina acarinata Subbotina Synonymy: Pseudoglobiquadrina Jenkins, 1966 Remarks: Acarinina is recognized here as including a large number of Paleocene and Eocene species with a pseudospinose wall, in most of which an imperforate carina is not developed along the peripheral margin. Test form is variable, but most species are either planoconvex or coni- cotruncate. Apertural position is also variable, ranging from umbilical to extra—umbilical or peripheral; these species, as a result, have been placed in either Globoro- talia or Globigerina by many authors. The concept used here is in general accord with that of most authors who have recognized this genus. Employed in this manner, Acarinina must be con sidered very largely as a form genus. Most of the phyto genies proposed for this group (Berggren, 1968, 197H>» McGowran, 1968) are not felt here to be sufficiently con vincing as to justify their use of taxonomic revision. A more recent and more detailed phyletic reconstruction (Samuel, 1972) has not been incorporated into this taxono mic system because it was not found until the manuscript 10^ was essentially complete* If this reconstruction is basi cally correct, Acarinina should probably include only those species descended from A. primitiva (Samuel, 1972, Tab. 3> 6, 8-ll). Of the forms here placed in this genus, only the A* convexa - A. mattseensis - A. pianodorsalis complex probably would be excluded. McGowran (1968, 1970) noted the presence of occa sional sutural accessory apertures in many acarininid and morozovellid species (see also Premoli Silva and Bolli, 1973) and suggested that both groups are probably poly- phyletic. His proposal that Acarinina and Morozovella should be recognized only as subgenera of Truncorotaloides has not been widely followed. If Samuel’s reconstructions are accepted, however, Acarinina would probably best be considered a junior synonym of Truncorotaloides. Acarinina alticonica Fleisher Acarinina mattseensis alticonica Fleisher, 197^a, PI. 2, Figs. 1-3 Remarks: Premoli Silva (personal communication) has suggested that this form, discussed in detail by Fleisher (l97^a), is identical with Globigerina subsphaerica Sub botina. From the holotype illustration and description, this seems unlikely because G. subsphaerica has fewer chambers in the final whorl, a lower spire, and a more 103 spherical overall test form. In the absence of comparative material, however, this possible synonymy cannot be dis proved. Strati^raphic Ran^e: This species is restricted to the Morozovella formosa - M. aragonensis Zone at Site 220. It is common in these samples. Acarinina apanthesma (Loeblich and Tappan) Globorotalia apanthesma Loeblich and Tappan, 1957a, PI. 59, Fig. 1. Globorotalia apanthesma Loeblich and Tappan, Krasheninnikov and Hoskins, 1973, PI. 18, Fig. 1-3. Acarinina apanthesma (Loeblich and Tappan), Fleisher, I975S7"P1. 1, Fig. 1. Remarks: The specimens observed here are closer to the holotype than are those illustrated by Krasheninnikov and Hoskins (1973). The presence of a peripheral keel on their specimens reflects the variability of this species. Secondary sutural apertures were noted on the dorsal sur faces of some of the specimens. Stratigraphic Range: A. apanthesma ranges from the Morozovella formosa - M. aragonensis Zone to the basal Globigerinatheka senni Zone at Site 220, 106 Acarinina boudreauxi Fleisher Plate 1, Figures 1, 2 Acarinina boudreauxi Fleisher, 1974a, PI. 1, Figs. 2-5* Remarks; The form with which A. boudreauxi can most readily be confused is probably A. punctocarinata. from which it may be distinguished by typically being smaller and more rounded in outline, by having a less open umbili cus, and by lacking the thickened peripheral margin of the latter species. Stratigraphic Range; This species is present at all three sites. Its overall range is from the base of the Globigerinatheka senni Zone (Site 220) to the upper portion of the Globigerinatheka curryi — G. euganea Zone (Site 237)* The range is very similar to that of A. punctocarinata. and the two species are probably closely related. Acarinina bullbrooki (Bolli) Globorotalia bullbrooki Bolli, 1957c, PI. 38, Figs. 4-5# Truncorotaloides densus (Cushman), McGowran and Lindsay, 1969, Figs. 7-13. Globorotalia spinuloinflata (Bandy), Samanta, 1970, PI. 3, Figs. 1-4*. Remarks: The references cited above reflect the taxonomic confusion that has surrounded this species. 107 Berggren (1968) suggested that A. bullbrooki should be considered a junior synonym of both Globigerina spinuloin- f lata Bandy, 19^99 and Pulvinulina crassata densa Cushman, 1925* Recently, as a result, Bollifs form commonly has been cited as "Globorotalia densa, 1 1 From the re illustrations of the holotypes of both older species (Cifelli, 1972), it is clear that all three species are distinct; P. crassata densa should be placed in a different genus (Morozovella) altogether. The morphotype illustrated by Bolli (1957c) as A, bullbrooki has been closely followed so as to define this species as rigidly as possible. Specimens assigned to this taxon have only four chambers in the final whorl, a narrow and elongate umbilicus, and a subacute to acute periphery, particularly in the final chamber. Stratigraphic Range: Rare specimens were observed in the Morozovella coronata — M. aragonensis Zone at Site 219. Acarinina cf. A. bullbrooki (Bolli) Remarks: A distinctive form observed at Site 237 appears to be closely related to A. bullbrooki, and may represent a variant with heavy secondary encrustation. The test wall appears to be much thicker than in typical specimens, and as a result the periphery is more rounded 108 and the umbilical region somewhat more closed. These specimens are thus somewhat more similar in appearance to Bolli*s paratype than to the holotype, Stratigraphic Range: Globigerinatheka senni and lower Morozovella coronata - M, aragonensis Zones at Site 237. Acarinina colomi (Bermudez) Plate 1, Figures 3» 5 Globigerina colomi Bermudez, 1961, PI, 2, Fig, 6, Remarks: Forms included here in A, colomi are some what similar to A, punctocarinata. The coiling is looser, however, and the chambers are accordingly more distinct and less closely appressed. The peripheral margin is subacute but there is no peripheral thickening or carinal develop ment, The umbilical chamber surfaces are more inflated than in A. punc to carinata, and the umbilicus is narrower and more elongate, A* colorni may be a junior synonym of Globigerina subcorpulenta Chalilov, but this cannot be determined from the holotype illustration of the latter, Stratigraphic Range: This species is found only in the upper portion of the Globigerinatheka senni Zone at Site 237. 109 Acarinina convexa (Subbotina) Globorotalia convexa Subbotina, 1953 (l97l)t PI# 17f Figs. 2, 3. Acarinina convexa (Subbotina), Fleisher, 1974a, PI. 1, Fig. 6>. Globorotalia (Acarinina) convexa Subbotina, Sigal, 1974» PI. 7, Fig. 1. Remarks; Berggren (1968) and McGowran (1968) traced the evolution of this species from Globigerina spiralis Bolli through Globorotalia pusilla s.l. Bolli, an interpretation which would suggest an evolutionary history independent of the other species here assigned to Acarinina. This pattern seems unlikely, however, as it involves the transition from a form with a cancellate wall to another with a finely perforate (?) wall, and finally to a descendent (A. convexa) with a pseudospinose wall. Comparative material is not immediately available from Leg 23 and Leg 24 samples to disprove this series, but in view of the apparent stability of wall types this conclu sion is tentatively rejected. Stratigraphic Range; Morozovella formosa - M, aragonensis Zone at Site 220. This approximates the upper limit cited by Berggren (1968). 110 Acarinina mattseensis mattseensis (Gohrbandt) Globorotalia mattseensis Gohrbandt, 1967* PI. 1, Figs. 25-30. Remarks: Most of the specimens reported as A. matt seensis mattseensis by Fleisher (1974a) do not properly be long in that taxon and are discussed below (as A. sp. l). Isolated forms observed at Site 237» however, correspond well with Gohrbandt•s illustrations and description. There is considerable intergradation between A. mattseensis s.s. and A. mattseensis wartsteinensis, and these forms are here considered to be related at the subspecies level. Of the criteria listed by Gohrbandt (1967) P°r the differen tiation of these forms, the greater biconvexity of A. matt seensis s.s. appears to be the most reliable. Stratigraphic Range: Very rare and isolated speci mens were recorded from the Globigerinatheka senni Zone at Site 237. Two questionable occurrences in the overlying Morozovella coronata - M. aragonensis Zone may be the re sult of contamination, but this cannot be determined with certainty. Acarinina mattseensis wartsteinensis (Gohrbandt) Globorotalia wartsteinensis Gohrbandt, 1967* PI* Figs. 18-24. Ill Acarinina wart steinensis (Gohrbandt), Fleisher, 197^a, p. 1013. Remarks: Gohrbandt (1967) proposed an evolutionary series from A. broedermanni (Globorotalia broedermanni of his report) through A. mattseensis s.s. to A. mattseensis wartsteinensis. This interpretation appears reasonable, although the taxonomy of A. broedermanni remains in doubt; the specimens illustrated by Bolli (1957a, PI. 19* Figs. 13-15; 1957c, PI. 37* Fig. 13) lack the strong and nearly equal biconvexity of the holotype. The basis for differentiating this form from A. mattseensis s.s. has been stated above. The specimens ob served here are similar to, but not quite as strongly planoconvex as Gohrbandt1s illustrations. Stratigraphic Range: The base of the range of A. mattseensis wartsteinensis is within the Globigerinatheka senni Zone at Sites 220 and 237. This seems to approximate the level reported by Gohrbandt (1967)* wh° concluded on incomplete evidence that the occurrence of this species was "not older than the Globorotalia palmerae Zone of Trini dad ..." (p. 323). At all three sites it ranges just above the base of the Morozovella coronata - M. aragonensis Zone • 112 Acarinina pentacamerata (Subbotina) Globorotalia pentacamerata Subbotina, 1947* Pi* 7* Pigs. 12-17. Acarinina pentacamerata (Subbotina), Subbotina, 1953 (1971), PI. 23, Fig. 8; PI. 24, Figs. 1-6. Acarinina pentacamerata pentacamerata (Subbotina), Krash eninnikov and Hoskins, 1973* PI. 3* Figs. 1—3• Acarinina pentacamerata (Subbotina), Fleisher, 1974a, PI. 1, Fig. 9. Remarks: A reasonable consensus appears to have developed witb respect to the morphology of this species. The proposed synonymy of A. pentacamerata with the older A* Pickannai (El—Naggar, 1966) is incorrect on both morpho logic and stratigraphic grounds. Stratigraphic Range: This species is present in the basal samples at Site 220, and ranges into the lower part of the Globigerinatheka senni Zone there and perhaps at Site 237, where it is represented by isolated occur rences in Core 237—32. Berggren (l971h) reported an over lap of A. pentacamerata and Hantkenina spp.; this longer range suggests that the extinction of A. pentacamerata may be geographically variable and thus stratigraphically un reliable . Acarinina pianodorsalis Fleisher Plate 1, Figures 6, 7* 8 / Globorotalia broedermanni Cusliman and Bermudez, Bolli, 113 1957c, PI. 37, Fig. 13. Acarinina planodorsalis Fleisher, 1974a, PI. 2, Figs. 6-9; PI. 3, Figs. 1-2. Remarks; This distinctive species can be recognized by the flattened dorsal surface and the roughened umbilical shoulders; some specimens are more strongly elevated on the umbilical side than is the holotype. Xt sppears to have been referred most commonly to A. broedermanni; the ex tinction of this form, as cited by Bolli (l957c) in Trini dad, corresponds in age with the extinction of A. plano dorsalis recorded here. Stratigraphic Range; A. planodorsalis first ap pears near the top of the Globigerinatheka senni Zone at Site 220. At the remaining two sites, it ranges to very near the top of the Morozovella coronata — M. aragonensis Zone , Acarinina pseudotopilensis Subbotina Acarinina pseudotopilensis Subbotina, 1953 (l97l), PI. 21, Figs. 8, 9; PI. 22, Figs. 1-4. Globorotalia (Acarinina) pseudotopilensis (Subbotina), Sigal, 197*1, PI. 7, Fig. 2. Stratigraphic Range; Rare specimens were found only in Sample 220-19-2, 45-47 cm. This sample is assigned to the Morozovella formosa - M. aragonensis Zone. 114 Acarinina punctocarinata Fleisher Globorotalia sp., Samuel, 1972, Tab* 8, Figs* 6, 7 (?)• Acarinina punctocarinata Fleisher, 197^a; PI* 3» Figs* 4-8. Remarks: Tbis species appears to be another of the forms that have probably been included by many authors in A. bullbrooki* It can be distinguished by the (typically) greater number of chambers in the final whorl (in adults, 5 as opposed to 4 in A. bullbrooki), the more open um bilicus, and in particular by the thickened peripheral margin. The holotype is heavily encrusted and represents a population strongly reduced by selective test dissolution. Assemblages from Site 237 contain specimens whose walls are much less thickened, and from these it can be seen that many tests of A. punctocarinata possess a true im perforate keel. The perforate "pseudocarina" originally described for this form is apparently a result of test wall thickening. The presence of this keel suggests that A. puncto carinata should be placed in Morozovella. The distinctly conicotruncate test form, however, seems to ally this species more closely with others (e.g., A. bullbrooki and A. boudreauxi) placed in Acarinina. The phyletic history proposed for this form by Samuel (1972), involving descent 115 from A. bullbrooki. supports this generic assignment. Stratigraphic Range: A. punctocarinata first ap pears within the Globigerinatheka senni Zone at Sites 220 and 237* At the former location it disappears within the Morozovella coronata - M. aragonensis Zone, but at Site 237 it ranges upward into the Globigerinatheka curryi - G. euganea Zone. Acarinina aff. A. punctocarinata Fleisher Plate 2, Figures 1, 2, 3 Remarks: Relatively small populations were ob served at Site 237 comprising specimens quite similar to A. punctocarinata but different in some distinctive re spects. These forms are more planoconvex than typical specimens and lack the apical (dorsal) cone of A. puncto carinata. These differences may represent no more than a lack of secondary thickening, and a pronounced keel is present, as is the dorsal "groove" separating the chambers of the final from those of the earlier whorl. The dorsal intercameral sutures are more oblique and less radial than those of A. punctocarinata. however, and the chambers are somewhat more arcuate in dorsal aspect. These forms, in fact, show a slight similarity to Morozovella acuta. They have been treated here as A. aff. A. punctocarinata. Stratigraphic Range; These forms were observed 116 only at Site 237» where they are virtually restricted to the Morozovella coronata — M. aragonensis Zone* Acarinina quetra (Bo11i) Globorotalia quetra Bolli, 1957a, PI* 19> Figs. 1-6* Acarinina quetra (Bolli), Fleisher, 197^a, PI. 3» Fig. 3* Remarks: A. quetra is similar to A. punctocarinata in possessing a well-developed keel on some specimens. Blow (l97l)> as a result, referred this species to Globorotalia (Morozovella)• In view of the overall test form and the sporadic nature of keel development, the placement of this form in Acarinina seems justified. Stratigraphic Range; This species was recovered only in the lower part of the Morozovella formosa — M. aragonensis Zone recovered at Site 220. Acarinina soldadoensis angulosa (Bolli) Globigerina soldadoensis angulosa Bolli, 1957a, PI. 16, Figs. V—6. Acarinina angulosa (Bolli), Berggren, 1971c, PI. 5> Figs. 13, i^* Acarinina soldadoensis angulosa (Bolli), Fleisher, 197^a, PI. h, Fig. 1. Remarks: This form is very similar to A. solda doensis s.s., and following the example of Bolli (1957a) 117 these two taxa are considered to be related at the sub species level. The angular umbilical margin and com pressed chambers provide the best basis Tor differentiating this from the nominate subspecies. Stratigraphic Range: This subspecies was observed only at Site 220, where it ranged from the basal recovered sediments (Morozovella formosa - M. aragonensis Zone) to within the Globigerinatheka senni Zone. The upper limits of its range are thus approximately the same as those noted by Berggren (l971to) and McGowran (l97^). Acarinina soldadoensis soldadoensis (Bronnimann) Globigerina soldadoensis Bronnimann, 1952, PI. 1, Figs. Figs. 1-9. Globigerina soldadoensis Bronnimann, Bolli, 1957a, PI. 16, Figs. 7-9. / 11 \ Acarinina soldadoensis (Bronnimann;, Berggren, 1971c, PI. 5, Figs. 1-3. / u \ Acarinina soldadoensis soldadoensis (Bronnimann), Fleisher, 197^a, PI. h, Fig. 2. Remarks: The specimens examined here were compared by 0. L. Bandy with Bronnimann1s holotype and judged to be fully conspecific with it. Stratigraphic Range: At Site 220 A. soldadoensis s.s. ranges from the M. formosa - M. aragonensis Zone to within the M. coronata - M. aragonensis Zone. At Site 237* 118 however, its highest occurrence is somewhat older— within the Globigerinatheka senni Zone— and it does not appear that the extinction of this species is a stratigraphically reliable horizon. Acarinina wilcoxensis (Cushman and Ponton) Globorotalia wilcoxensis Cushman and Ponton, 1932a, PI. 9, Fig. 10. Globorotalia wilcoxensis Cushman and Ponton, Bolli, 1957a, PI. 19, Figs. 7-9. Acarinina wilcoxensis (Cushman and Renz) (sic), Berggren, 1971c, PI. 5, Figs. k, 5. Acarinina pseudotopilensis Subbotina Krasheninnikov and Hoskins, 1973, PI. 3, Figs. 7-9. Acarinina wilcoxensis (Cushman and Ponton), Fleisher, 197^a, p. 1014. Remarks: The ventral surfaces of the chambers of the forms illustrated as G. wilcoxensis by Bolli (l957a) are somewhat more inflated than are those of the holotype. The specimens observed here are intermediate between the holotype and Bollifs forms. Stratigraphic Range: This species was found only in Cores 16 through 19 (Morozovella formosa - M. aragonen sis Zone) at Site 220. 119 Acarinina sp, 1 Plate 2, Figures 4, 5 Acarinina mattseensis mattseensis (Gohrbandt), Fleisher, 1974a, PI. 1, Figs. 7, 8. Remarks: Acarinina sp. 1 includes large populations of relatively small and high-spired forms that Fleisher (1974a) referred to A. mattseensis mattseensis. This identification now appears to be incorrect. These small forms typically have six chambers in the final whorl, although stratigraphically younger populations frequently include specimens with five. The chambers are moderately inflated and distinct. Small specimens may be almost equally biconvex, but the larger forms show a dis tinctly high spire, primarily because of the height of the final whorl. The aperture is a moderately low arch, com monly bordered by a distinct lip, which opens into the re- lately small umbilicus. The wall is pseudospinose, with pseudospines concentrated along the umbilical shoulders. Acarinina sp. 1 is somewhat similar to Globigerina spiralis of Bolli (1957a), but the latter was described as having a cancellate wall. Globigerina aquiensis of Loeb- lich and Tappan (1957) is also similar in form, but has fewer chambers per whorl. The strongest similarity seems to be with the Paleocene—Early Eocene species Globigerina (= Acarinina) chaseanona Loeblich and Tappan. Stratigraphic Range: The range of this species is 120 from tlie upper part of the Morozovella formosa — M. aragonensis Zone at Site 220 to within the Morozovella coronata - M. aragonensis Zone at Sites 220 and 237* / GENUS Cassigerinella Pokorny, 1955 ✓ Type Species: Cassigerinella boudecensis Pokorny (= junior syncnym of Cassidulina chipolensis Cushman and Ponton). Remarks; The origin of Cassigerinella is not known. The enrolled biserial chamber arrangement suggests affinities with Chiloguembelina. but the early planispiral stage (Cordey, 1968) and the toothplate noted in chi polensis (llofker, 1963; Steineck and Darrell, 1971) cast doubt on this hypothesis, Xt is possible, indeed, that Cassigerinella represents an independent nonglobigerinacean adoption of planktonic habit, but there is no direct evi dence to support this conclusion, Cassigerinella chipolensis (Cushman and Ponton) Cassidulina chipolensis Cushman and Ponton, 1932b, PI, 15, Fig, 2, / Cassigerinella boudecensis Pokorny, 1955> Figs, 1—3* Cassigerinella globolocula Ivanova in Bykova, 1958, PI, 11, Figs. 1-3. Cassigerinella chipolensis (Cushman and Ponton), Fleisher, I97^a, PI. 4, Fig. 3. 121 Remarks; Cassigerinella ciiipolensis appears to be only moderately resistant to test dissolution* In sedi ments from the interval representing its known range, this species appears only sporadically, and even then typically as isolated specimens* Stratigraphic Range: Isolated occurrences were noted in the Early Oligocene and Early Miocene at Site 219* This species is somewhat more commonly present, although it is typically represented by only a few specimens, from the Globoquadrina binaiensis through Globigerinatella in— sueta Zones at Site 237* GENTJS Catapsydrax Bolli, Loeblich, and Tappan, 1957 Type Species: Globigerina dissimilis Cushman and Bermudez• Remarks: Catapsydrax was originally distinguished from its approximate isomorph Globigerinita by the nature of the umbilical bulla. In Catapsydrax the bulla was felt to be consistently small and restricted to the umbilicus, with few infralaminal accessory apertures, as opposed to the larger and more extensive bulla with numerous secondary apertures "all along its margins" (Bolli e_t suL. , 1957* P* 36) of Glob igerinita. Banner and Blow (1959) accepted this basis of differentiation, but subsequently (Blow and 122 Banner, 1962) concluded tliat "these distinctions are of no more than specific character . . . " (p. 104), Their interpretation has been very widely followed. This recombination, based on the putative importance of apertural modifications as a primary taxonomic feature, overlooks the significant differences in wall texture, stratigraphic distribution, and phylogeny which distinguish these two taxa. Species properly assigned to Globigerinita possess a microperforate wall (Fleisher, 1974a, PI. 9> Figs. 1~3), in direct contrast to the distinctly cancellate non— spinose texture typical of Catapsydrax dissimilis and other species properly assigned to this genus (Fleisher, 1974a, PI. 4, Figs. 4-8; Poag, 1972, PI. 10, Figs. 7-10). This distinction is readily observable in reflected light and appears to reflect fundamental differences in test wall construction. Catapsydrax is primarily aL Paleogene genus, originat ing in the Eocene (probably from Globorotaloides suteri or O* turgidus) and reaching maximum diversity in the mid- Oligocene before becoming extinct in the Early Miocene. Globigerinita evolved quite independently of this group from Tenuitella clemenciae in the Late Oligocene. The earliest species, G. boweni, gave rise to a persistent and long-ranging species complex that is widely distributed in Neogene sediments. 123 These two genera represent gross isomorphs in that both are typified by umbilical bullae, but they are almost completely unrelated. They have accordingly been treated here as separate and distinct taxa. Catapsydrax africanus (Blow and Banner) Globigerinita africana Blow and Banner, 1962, PI. 15» Figs. A, B. Globigerinita africana Blow and Banner, Blow, 19&9* PI* 24, Figs. 1, 4. Globigerinita africana Blow and Banner, Samanta, 1970, PI. 2, Figs. 1, 2. Catapsydrax africanus (Blow and Banner), Fleisher, 1974a, p. 1015. Remarks: Blow and Banner (19^2) described the wall of iC. africanus as "uniformly and moderately coarsely per forate; its surface is punctate and distinctly, densely and finely hispid1 1 (p. 106) . No indication of this hispidity is apparent either in the holotype drawing or in the scanning electron micrograph of the metatype selected by Blow (1969). These illustrated specimens appear to be fully cancellate and nonspinose, as are the few specimens recorded in the present study. The authors apparently interpreted as spine bases the nodes commonly formed by the intersection of interpore ridges; it is also possible, of course, that C. africanus (and presumably other species of Catapsydrax as well) bore acicular spines in life, but this 124 cannot be verified. On the other hand, it seems likely that Catapsydrax evolved from Globorotaloides. whose only living representative (G. hexagonus) is known to be non- spinose (Parker, 1962). Stratigraphic Range: Samanta (1970) has reported this species as low as the Orbulinoides beckmanni Zone; this range cannot be verified here, but occasional speci mens were noted in sediments from the Truncorotaloides pseudodubius and Globigerinatheka semiinvoluta Zones at Sites 219 and 237. Catapsydrax dissimilis ciperoensis (Blow and Banner) / Catapsydrax dissimilis (Cushman and Bermudez), Bolli et al., 1957, PI. 7, Fig. 8 only. Globigerinita dissimilis ciperoensis Blow and Banner, 1962, PI. l4, Figs. A, B, C. Globigerinita dissimilis ciperoensis Blow and Banner, Blow, 1969, PI. 2 4 , Fig. 2. Globigerinita ciperoensis Blow and Banner, Poag, 1972, PI. 10, Figs. 5,6. Catapsydrax dissimilis ciperoensis (Blow and Banner), Fleisher, 1974a, PI. h, Fig. 4." Remarks: This form differs from the nominate sub species primarily in the number of accessory infralaminal apertures, although Blow and Banner (1962) cited other less distinctive criteria as well. The specimens observed here are quite similar to the holotype, but somewhat less 125 lobate in outline than the specimen illustrated by Blow (1969). Poag (1972) has elevated this taxon to full species status, but this interpretation does not seem justified in view of the broad similarity between these two subspecies. It may be that Poag's identification is in error, as the bulla on his illustrated specimen is considerably larger than is typical for this form. Stratigraphic Range: Very rare occurrences of this form in the Globigerinatella insueta Zone at Site 219 are almost certainly reworked contaminants. At Site 2379 this form ranges from the "Turborotalia" opima opima Zone to the top of the Catapsydrax dissimilis Zone. It is a persistent faunal element in the ! , T. " opima s. s. and Globoquadrina binaiensis Zones at Site 220. / Catapsydrax dissimilis dissimilis (Cushman and Bermudez) Globigerina dissimilis Cushman and Bermudez, 1937» PI# 3* Figs. 5—6• / Catapsydrax dissimilis (Cushman and Bermudez), Bolli e_t al., 1957> PI# 7> Figs. 6, 7 only. / Globigerinita dissimilis dissimilis (Cushman and Bermudez), Blow and Banner, 1962, PI. l4, Fig. D. / Globigerinita dissimilis (Cushman and Bermudez), Raju, 1971, PI. 6, Fig. 2 only. 126 / Catapsydrax dissimilis dissimilis (Cushman and Bermudez), Fleisher, 1974a, PI* Fig. 5* Remarks: See comments above for CL dissimilis ciperoensis * Stratigraphic Range: This species was not observed at Site 219* At Sites 220 and 237> it occurs as isolated specimens in most samples from the Globoquadrina binaien- sis Zone to the Catapsydrax dissimilis Zone. The lower portion of* the range recorded elsewhere for CL dissimilis s.s. (i.e., within the Late and perhaps Middle Eocene; see Blow, 1969; Raju, 1971) was not observed. Catapsydrax globiformis (Blow and Banner) Globigerinita globiformis Blow and Banner, 1962, PI. 14, Figs. S, T, U. Catapsydrax globiformis (Blow and Banner), Fleisher, 1974a, PI. 4, Fig. 6. Remarks: This species can be distinguished by the globular test form and the extensive and embracing but not highly inflated bulla. The comments on wall texture recorded for CL africanus apply to this species as well. Many of the Middle and Late Eocene species of Catapsydrax— CL globif ormis . C_. africanus . CL howei . and CL martini s.l., in particular— are only very rarely en countered in deep-sea deposits. These forms, clearly, are 127 highly susceptible to test dissolution. Stratigraphic Range: Very rare specimens were ob served in the Globigerinatheka semiinvoluta Zone at Site 219. Catapsydrax martini martini (Blow and Banner) Globigerinita martini martini Blow and Banner, 1962, PI. l4, Fig. 0. Globigerinita martini martini Blow and Banner, Blow, 1969, PI. 24, Fig. 5. Catapsydrax martini (Blow and Banner), Fleisher, 197^a, p. 1016. Remarks: This very small Form can be recognized by its inflated bulla. Again, the species was described (Blow and Banner, 1962) as both coarsely perforate and coarsely hispid; Blow’s (1969) illustration suggests that although the bulla appears to be finely perforate, the chamber walls are truly cancellate. Stratigraphic Range: £. martini martini ranges from the Truncorotaloides pseudodubius Zone to the top of the Globigerinatheka semiinvoluta Zone at Site 237. Its ab sence in the Turborotalia cerroazulensis Zone may be the result of test dissolution, as a single specimen was ob served in the Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone at Site 219. 128 Catapsydrax parvulus Bolli, Loeblich, and Tappan Catapsydrax parvulus Bolli, Loeblich, and Tappan, 1957 > PI. 7, Fig. 10. Globigerinita parvula (Bolli, Loeblich, and Tappan), Bronnimann and Resig, 1971 > PI. 24, Figs. 5-7 • Remarks: The wall of this form is smoother than that of most typical species of Catapsydrax, although it is not microperforate. Specimens of C_. parvulus are rare in these samples, and on the basis of more extensive populations it may be desirable to reassign this species to a different genus. Stratigraphic Range: Very rare specimens were ob served in the uppermost Catapsydrax dissimilis and lower Globigerinatella insueta Zones at Site 237* This is con siderably lower than the initial appearance cited by Blow (l969)> but the material is too scanty at this site to justify emendation of the published range. Catapsydrax perus (Todd) Globigerina pera Todd, 1957> PI. 70» Figs. 10, 11. Globigerinita pera (Todd), Blow and Banner, 1962, PI. l4, Figs. E, F, G, H. Catapsydrax perus (Todd), Fleisher, 1974a,PI. 4, Fig. 7* Stratigraphic Range: This species ranges from the 129 top of the Truncorotaloides pseudodubius Zone at Site 219 to very near the top of the Globoquadrina binaiensis Zone at Site 237* This distribution closely approximates the range cited by Blow (1969)* Catapsydrax riveroae (Bermudez) / Globigerinita riveroae Bermudez, 1961, PI. 7> Fig. 7* Remarks: This species is distinguished by the long narrow bulla from (3 . perus, which it somewhat resembles. Blow (1969) indicated the likelihood of a close relation ship between C_. riveroae and Subbotina winkleri. If cor rect, this affinity would suggest the placement of C. riveroae in Subbotina. It should be noted that the function and hence the significance of umbilical (apertural) bullae are unknown; the parallel development of this feature in several globigeriniform groups would not be surprising. Stratigraphic Range: £. riveroa is confined to the upper "Turborotalia" opima opima and Globoquadrina binaien sis Zones at Sites 220 and 237* It was not observed at Site 219. Catapsydrax stainforthi Bolli, Loeblich, and Tappan Plate 2, Figure 6 Catapsydrax stainforthi Bolli, Loeblich, and Tappan, 1937> PI. 7, Fig. 11. 130 Globigerinita stainforthi (Bolli, Loeblich, and Tappan), Blow, 1969, PI. 25, Figs. 8-10. Catapsydrax stainforthi Bolli, Loeblich, and Tappan, Postuma, 1971, P- 258. Globigerinita stainforthi (Bolli, Loeblich, and Tappan), Raju, 1971, PI. 6, Fig. 4. Stratigraphic Range: Very rare specimens were ob served near the top of the Catapsydrax dissimilis Zone at Site 237* C,* stainf orthi is apparently particularly sus ceptible to test dissolution. Catapsydrax unicavus primitivus (Blow and Banner) Globigerinita unicava primitiva Blow and Banner, 1962, PI. 14, Figs. J, K, L. Globigerinita unicava unicava (Bolli, Loeblich, and Tappan), Blow, 19&9, FI. 25, Figs. 1, 2. Catapsydrax unicavus primitivus (Blow and Banner), Fleisher, 1974a, p. 1016. Remarks: Fleisher (1974a)discussed the problems involved in distinguishing this subspecies from CL uni cavus s.s. Xn brief, the criteria cited by Blow (1969) are precisely the reverse of those indicated by Blow and Banner (1962). In each case, the illustrated specimen is in accord with the respective definitions. The earlier holotypic concept is followed here. Stratigraphic Range: CL unicavus primitivus is con sistently rare, and its occurrences are sporadic. It 131 ranges from the Turborotalia cerroazulensis Zone at Site 219 into the "Turborotalia" kugleri Zone at Site 237* Catapsydrax unicavus unicavus Bolli, Loeblich, and Tappan Catapsydrax unicavus Bolli, Loeblich, and Tappan, 1957* PI. 7, Fig. 9* Globigerinita unicava unicava (Bolli, Loeblich, and Tappan), Blow and Banner, 19&2, PI* 1^- > Figs. M, N. Globigerinita unicava primitiva (Blow and Banner), Blow, 1969, PI. 25, Figs. 1, 2. Globigerinita unicava (Bolli, Loeblich, and Tappan), Poag, 1972, PI* 10, Figs. 9, 10. Catapsydrax unicavus unicavus Bolli, Loeblich, and Tappan, Fleisher, 197^+a, p. 10l6. Remarks: See comments above for C.. unicavus primitivus. Some difficulty has also been encountered in differentiating £. unicavus s.s. from Globorotaloides suteri, and these two species appear to be related. The latter is distinguished by its noticeably flattened spiral side • Stratigraphic Range: Occurrences are rare and sporadic at all three sites. At Site 219, it occurs only in the upper part of the Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone; a single specimen in the Late Miocene is clearly reworked. At Site 220, £. unicavus s.s. is limited to the upper part of the 132 "Turborotalia” opima opima Zone, and at Site 237 it occurs only within the Globigerinatheka semiinvoluta and basal Turborotalia cerroazulensis Zones. This pattern is incon clusive, but it seems to correspond with the range cited by Blow (1969) for C. unicavus primitivus. Catapsydrax sp. 1 Plate 2, Figures 7* 8 Remarks: The specimens included here in Cata psydrax sp. 1 are small, thick—walled forms commonly but not universally possessing an inflated umbilical bulla. The single accessory aperture located at the posterior margin of the bulla is rimmed with a small but distinct lip. The test wall is cancellate and apparently non- spinose, but wall characteristics are somewhat difficult to determine in detail because of the pronounced wall thickening. The subglobular and relatively distinct chambers are arranged in a moderately high trochospire, and the spiral side is distinctly convex. In nonbullate specimens the primary aperture consists of an arched open ing into the distinct umbilicus. Stratigraphic Range; This species was found only within the Globigerinatheka curryi — G. euganea Zone at Site 237* It is rare throughout most of its range at this locality. 133 GENUS Chiloguembelina Loeblich. and Tappan, 195^ Type Species; Guembelina midvayensis Cushman. Synonymy; Chiloguembelinella El-Naggar, 1971* Remarks: These forms are common in deep-sea populations because they appear to be relatively resistant to test dissolution. Because of their small size, how ever, species of this genus have received inadequate at tention; morphologies and stratigraphic ranges are thus poorly known. Chiloguembelina cubensis (Palmer) Guembelina cubensis Palmer, 193^* Figs. 1-6. Chiloguembelina cubensis (Palmer), Beckmann, 1957* PI* 21, Fig. 21. Chiloguembelina spp. ex group cubensis (Palmer), Blow, 1969, PI. 54, Figs. 4-6. Chiloguembelina cubensis (Palmer), Fleisher, 1974a, PI. 4, Fig. 8. Stratigraphic Range; The most complete range for this form is expressed at Site 237, where C. cubensis ranges from the Truncorotaloides pseudodubius Zone to the "Turborotalia" opima opima Zone. The isolated and very rare occurrences of this small species above this level are probably reworked. It should be noted that Berggren and Amdurer (1973) have noted the extinction of _C. cuben- 13^ sis within the Globorotalia opima opima Zone of Bolli (1966a). This finding lends support to the erection by Jenkins and Orr (1972) of a zone (see Fig. 9) whose top is defined by this event* The single sample at Site 237 as signed to the "T," opima opima Zone contains numerous specimens of £. cubensis * but because it lies directly above an unconformity spanning most of the Early Oligocene there is no way of determining whether or not these speci mens are also reworked. Xf not, the joint disappearance of C. cubensis and ”T.M opima opima between Sample 237-22- CC and Sample 237-22-3, 79-81 cm, probably indicates the presence of an unconformity representing the upper part of the MT." opima opima Zone. C. cubensis and C. martini were not distinguished at Site 219* and the respective ranges of these species were thus not determined. Chiloguembelina martini (Pijpers) Textularia martini Pijpers, 1933* P* 57* Figs. 6-10. Chiloguembelina martini (Pijpers), Beckmann, 1957* Fig. 14, Nos. 9-11, i 4 - 187 20-23; FI. 21, Fig. 14. Remarks; Beckmann (1957) discussed the morphologic variability of this form. Stratigraphic Range: This species ranges from the base of the Morozovella coronata - M. aragonensis Zone to 135 the Turborotalia cerroazulensis Zone at Site 237* Thus agrees well with the distribution cited by Beckmann (1937)* For the stratigraphic range at Site 219, see the comments above for C. cubensis. GENUS Clavigerinella Bolli, Loeblich, and Tappan, 1957 Type Species: Clavigerinella akersi Bolli, Loeb lich, and Tappan. Remarks: The overall morphology of these forms has been discussed in some detail by Bolli et al. (1957) and by Postuma (l97l)* The surface wall texture, however, has received little treatment beyond cursory examination by Lipps (1966). The wall appears to consist of a network of weakly developed interpore ridges surrounding shallow and densely packed pore pits. This pattern is similar to that observed in the wall of Hantkenina spp., to which the two known species of Clavigerinella are probably related. Clavigerinella akersi Bolli, Loeblich, and Tappan Clavigerinella akersi Bolli, Loeblich, and Tappan, 1957, PI. 3, Pig. 5. Clavigerinella akersi Bolli, Loeblich, and Tappan, Postuma, 1971, P# 132. Stratigraphic Range; A single specimen was found 136 in Sample 237-27"-6, 7^—76 cm, in the upper part of* the Morozovella coronata - M. aragonensis Zone, The scarcity of* this species, as well as of* jC. .jarvisi, suggests that these species, like Iiantkenina spp., are readily dis solved in the deep sea, Clavigerinella .jarvisi (Cushman) Plate 3* Figures 1, 2 Hastigerinella .jarvisi Cushman, 1930* PI* 3* Figs. 8—11. Clavigerinella .jarvisi (Cushman), Bolli, 1937c, PI. 35* Figs. 5, 6. Clavigerinella .jarvisi (Cushman), Postuma, 1971* P* 132. Stratigraphic Range: Rare occurrences of* this species were noted in a few samples near the top of* the Globigerinatheka senni Zone at Site 237* This is presum ably slightly below the level of* Berggren's (1971b) "Hantkenina Datum1 1 and thus extends the base of* the range for C_. .jarvisi somewhat below the level at which he re ported it. GENUS Globanomalina Haque, 1956 Type Species: Globanomalina ovalis Haque ( = junior synonym of* Globorotalia chapmani Parr) , Synonymy; Planorotalites Morozova, 1959* Remarks: The species here placed in Globanomalina 137 include a number of forms which collectively are closely isomorphic with the Neogene genus Globorotalia, Despite the strong similarities in overall test morphology and surface wall texture (both groups appear to have finely perforate walls), there is no indication of a phylogenetic relationship. The youngest clearly established species of Globanomalina, G. laccadivensis, ranges no higher than the Late Eocene Turborotalia cerroazulensis Zone, By contrast, Globorotalia (as defined here) evolved no earlier than Early Miocene, and its ancestry is sufficiently well known to preclude the possibility of this genus having evolved from a species of Globanomalina (Fleisher, 197^a), Thus from purely phylogenetic considerations, and in contrast to general practice (e.g., Postuma, 1971, Blow, 1971> Premoli Silva and Bolli, 1973)> the name Globorotalia should not be applied to the Paleogene species. Most authors (e.g., McGowran, 1968; Berggren, 1971b; Sigal, 197^) who have recognized this distinction have placed these Paleogene species in Planorotalites. The holotype of Globanomalina ovalis (Berggren et al., 1967)is slightly trochoid rather than planispiral, how ever, and should be considered a junior synonym of Globorotalia chapmani Parr. Globanomalina is thus the oldest generic name applied to this lineage (McGowran, 1968, lineage 6), and following Steineck (l971b) it is given priority over Planorotalites. Xt should be noted 138 that if the synonymy of Globanomalina ovalis and Globoro talia chapman! is not accepted (see Jenkins, 197l)» Globanomalina becomes a senior synonym of Pseudohasti^erina for* plankspiral Eocene and Oligocene species. Globanomalina laccadivensis Fleisher Plate 3, Figures 3> ^ Globanomalina laccadivensis Fleisher, 197^+a-*Pl* 5* Figs. 7-12. Remarks: This small form has been discussed at some length (Fleisher, 197^-a)» and little more needs to be added* No species morphologically intermediate between G. laccadivensis and T. primitiva, and no form similar to either in the stratigraphic interval between them, was ob served at Site 237* The relationship, if any, between these two species thus remains unclear. Stratigraphic Range; Globanomalina laccadivensis ranges from the Truncorotaloides pseudodubius Zone to the Globigerinatheka semiinvoluta Zone at Site 237 and slightly into the Turborotalia cerroazulensis Zone at Site 219* Globanomalina pseudoscitula (Glaessner) Globorotalia pseudoscitula Glaessner, 1937> p* 32, Fig. 3* Globorotalia renzi Bolli, 1957c, PI. 38, Fig. 3. Globorotalia pseudoscitula Glaessner, Schmidt and Raju, 1973, PI- 1, Figs. 3, h. 139 Globanomalina pseudo sc i tula (Glaessner) , Fleisher, 197^a, PI. 6, Figs. 1, 2. Remarks: Tliis species appears to have given rise to G. laccadivensis in the late Middle Eocene (see Fleisher, 1974a, PI. 5, Fig. ll). Stratigraphic Range; Globanomalina pseudoscitula ranges from the lowest recovered samples in the Morozovella formosa — M. aragonensis Zone (Site 220) to the top of the Truncorotaloides pseudodubius Zone (Sites 219, 237)* GENUS Globigerina d'Orbigny, 1826 Type Species: Globigerina bulloides d'Orbigny. Remarks: This generic name has been applied to more species of planktonic foraminifera than any other, primarily because it is typically defined to include all trochospiral forms with an umbilical apertural position. Some authors (e.g., McGowran, 1968, 197^, Steineck, 1971b) have recently recognized the value of the genus Subbotina as a taxon comprising Paleogene species with an apertural lip and cancellate wall. The concept of Globigerina employed here, based largely upon considerations of wall texture and phylogeny, is even more restrictive. Only species with a trochospiral chamber arrangement and a spinose wall are included, and 140 all but one of these (Globigerina obesa) have an aperture which is umbilical in position. The use of these morphological criteria is justi fied by examination of the phylogeny of these species, which suggests that the spinose globigerinids form a natural evolutionary grouping consisting of several sub lineages. The ultimate ancestor of Globigerina is not known, but the oldest spinose form appears to be G. of ficinalis . This species gave rise to three separate but closely related and morphologically similar sublineages: (l) G. praebulloides to G. bulloides and G. calida; (2) the G. ouachitaensis species complex; and (3) the G. anguliof- ficinalis - G. angulisuturalis sublineage. The primary practical effect of restricting Globigerina in this manner is to exclude a number of un related species which also possess umbilical apertures. These include the species placed in Subbotina, the large Eocene-Oligocene globigeriniform species of the Globo- quadrina tripartita-tapuriensis-sellii-binaiensis complex, and the Oligocene to Holocene lineage of 1 1 Globigerina1 1 composed of such species as "G. 1 1 woodi, "G. ” nepenthes. and "G. 1 1 decoraperta. Globigerina is thus primarily a mid— Tertiary genus; the only living species are G. bulloides and G. calida. l4l Globigerina anguliofficinalis Blow Plate 3* Figure 6 Globigerina anguliofficinalis Blow, 1969, PI. 11, Figs. 1-5. Remarks: Tbis species may be difficult, where very few specimens are present, to differentiate from juveniles of its descendent, G. angulisuturalis. Stratigraphic Range: Very rare specimens were ob served at Site 237 in the "Turborotalia" opima opima and Globoquadrina binaiensis Zones. One possible specimen was also found in the "Turborotalia" kugleri Zone. Globigerina angulisuturalis Bolli Plate 3* Figure 5 Globigerina ciperoensis angulisuturalis Bolli, 1957b, PI. 22, Fig. 11. Globigerina angulisuturalis Bolli, Blow, 1969, PI. 1, Figs. l-3> PI. 11, Figs. 8, 9» PI. 12, Figs. 1, 2. Stratigraphic Range: This species occurs only as very rare isolated specimens in the "Turborotalia" opima opima and Globoquadrina binaiensis Zones at Site 237. The absence of this and the preceding species at Site 219, coupled with its presence at nearby Pondicherry (Raju, 1970), suggests that these forms are easily dissolved and hence stratigraphically unreliable in deep-sea associa tions • ikZ Globigerina cf. G. angulisuturalis Bolli Remarks: Included here is a small form with five to six chambers in the last whorl of a very flat trochospire. It is broadly similar in form to G. angulisuturalis, but the sutural channels are much less distinct. The aperture is a relatively high umbilical to extraumbilical arch, and is bordered in some specimens by a distinct lip or flange. The chambers are globular to subglobular and distinct, and dorsal sutures are radial. The wall texture of this form is unclear, but appears to be similar to that of G. angulisuturalis. Stratigraphic Range: G. cf. G. angulisuturalis occurs at a few horizons in the Globoquadrina binaiensis Zone • Globigerina ciperoensis Bolli Globigerina ciperoensis Bolli, 1954, Figs. 3-6. Globigerina ciperoensis ciperoensis Bolli, Bolli, 19571>* PI. 22, Fig. 10. Globigerina ouachitaensis ciperoensis Bolli, Blow, 1969* PI. 2, Figs. 4-6; PI. 17, Figs. 7, 10, 11. Stratigraphic Range: Single specimens were noted at two horizons in the Globoquadrina binaiensis Zone at Site 237. 1^3 Globigerina obesa (Bolli) Globorotalia obesa Bolli, 1957b, PI. 29, Figs. 2, 3* Globorotalia (Turborotalia) obesa Bolli, Blow, 19&9, P 352. Remarks: Despite the extraumbilical apertural posi tion, the spinose wall (Bolli, 1957b) strongly indicates affinities with the species included in Globigerina rather than Globorotalia. Stratigraphic Range: G. obesa is rather consistently present at Site 237 above its appearance in the upper part of the Globoquadrina binaiensis Zone. Globigerina officinalis Subbotina Globigerina officinalis Subbotina, 1953 (l97l), Pi* H, Figs. 1-7. Globigerina officinalis Subbotina, Blow and Banner, 19^2, PI. 9, Figs. A, B, C. Stratigraphic Range; A single specimen of G. of ficinalis was recovered from Sample 237-26-2, 79-81 cm, in the Globigerinatheka curryi - G. euganea Zone. Globigerina ouachitaensis Howe and Wallace Globigerina ouachitaensis Howe and Wallace, 1932, PI. 10, Fig. 7. ihb Globigerina ouachitaensis ouachitaensis Howe and Wallace, Blow and Banner, 19^2, PI. 9* Figs. D, H, I, J, K. Globigerina ouachitaensis ouachitaensis Howe and Wallace, Blow, 1969, PI# 17, Figs. 3, 4# Remarks: Xn view of the very small populations ob served in these sediments, no attempt has been made to recognize the subspecies of G. ouachitaensis differentiated by Blow and Banner (1962) and Blow (1969)# Stratigraphic Range: Specimens of G. ouachitaensis were noted only within the Globoquadrina binaiensis Zone at Site 237# Globigerina praebulloides occlusa Blow and Banner Globigerina praebulloides occlusa Blow and Banner, 1962, PI. 9, Figs. U, V, W. Globigerina praebulloides occlusa Blow and Banner, Blow, 1969, PI. 1, Pigs. 10, 11. Globigerina praebulloides occlusa Blow and Banner, Fleisher, 1974a, p. 1018. Stratigraphic Range: A single occurrence was noted at Site 219, within the Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone. Globigerina praebulloides praebulloides Blow Globigerina praebulloides Blow, 1959> PI# 8, Fig. 47; PI. 9, Fig. 2t8. 145 Globigerina praebulloides praebulloides Blow, Blow and Banner, 1962, PI. 9» Figs. 0, P, Q. Globigerina praebulloides praebulloides Blow, Blow, 1969, PI. 2, Figs. 7-9. Globigerina praebulloides praebulloides Blow, Fleisher, 1974a, p. 1019. Remarks: No attempt has been made here to dis tinguish the subspecies of this taxon, primarily because of the scarcity of specimens. Stratigraphic Range: At Site 219 a single occur rence of relatively common specimens was noted in Sample 219-16-4, 52-54 cm, in the Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone. At Site 237 rare occurrences were noted over the interval between the uppermost Turborotalia cerroazulensis and the lowermost Catapsydrax dissimilis Zones. GENUS "Globigerina. 1 1 non Globigerina dfOrbigny Remarks: This informal taxon is used here, as by Fleisher (1974a), to include a number of species that have been referred consistently to Globigerina by most authors, but which are morphologically and phyletically distinct from the species of that genus. The species assigned to "Globigerina" share a number of diagnostic morphological characters which serve to distinguish them from Globigerina. The most important of these is wall texture. The wall of Globigerina has al- 146 ready been described, and consists of a flat surface sup porting acicular spines or spine bases and penetrated by cylindrical pores. In contrast to tbis spinose texture, tbe species of "Globigerina” have a distinctly cancellate spinose test. Pores are located at tbe base of pore pits which are separated by distinct interpore ridges; both pits and ridges are absent from tbe wall of Globigerina, Although modern representatives possess acicular spines when living (Parker, 1962), spine bases are not as dominant a factor in the appearance of the wall as in Globigerina, The wall of “Globigerina1 1 appears coarsely perforate in reflected light, and in practice there is no significant difficulty involved in distinguishing the species of these two taxa, A number of additional morphological characteristics are common to all or most species of this group. Most distinctive of these is a well—developed imperforate apertural rim or lip. Almost all species of “Globigerina” also have closely appressed chambers, unlike the loosely attached chambers of many species of Globigerina (e.g., G. bulloides, G. praebulloides, G. calida), and most have low and narrow apertures. The most distinctive and character istic features, however, are the cancellate spinose sur face wall texture and the apertural lip. These species also appear to share a phyletic his tory independent of the species of Globigerina (Fig. ll), 147 Figure 11. Phylogenetic pattern of coarsely perforate species of ' ’Globigerina, ; t Ilanc;es of individual species may differ somewhat in extra-1ropica1 strati.graphic sequence s , Middle Miocene Oligocene Early Miocene Pleistocene Late Miocene Pliocene 00 N pseudodruryi nepenthoides woodi connects tenella bo ttii woodi woodi rubescens decoraperta y sallentina druryi apertura nepenthes foliata buibosa parabulloides Globigerinoides spp. although the details of this evolutionary pattern are not well known. The earliest species properly placed with certainty in this group appears to be “G, “ woodi woodi, which evolved in the Late Oligocene and was probably ancestral, with "G, 1 1 woodi cormecta, to the Neogene repre sentatives of this genus. The direct ancestor of ”G." woodi woodi has not been clearly established, but it probably evolved from a species with a morphology similar to that of ?"G. “ labiacrassata (Jenkins) , Jenkins (1966, 197l) illustrated several species, including Globigerina brazieri and G . labiacrassata, whose morphologies suggest an affinity with "Globigerina." The ultimate ancestor of this group may be Globigerina ampliapertura of Bolli (= "Turborotalia" ampliapertura of this report), a pos sibility originally suggested by Wade (1964). Until this early ancestry has been established, however, and the full evolutionary relationship of this group recognized, it seems premature to erect a new generic name for these species. The sublineages within “Globigerina, 1 1 to the extent that they are demonstrable, have been discussed by Fleisher (197^3-) , and no additional comments appear warranted, “Globigerina” nepenthoides (BrSnnimann and Resig) Plate 3* Figure 7 1 ! Globigerina nepenthoides Bronnimann and Resig, 1971» PI* 7, Figs. k - 9 . Remarks: This species is a close isomorph of the Middle Miocene to Pliocene form "G,” nepenthes, but the stratigraphic ranges of these two taxa differ markedly. Bronnimann and Resig (1971) di scussed the morphologic dif ferences. Some difficulty was encountered in distinguish ing "G." nepenthoides from "G." pseudodruryi. a form with which these authors did not compare it. "G." nepenthoides differs from "G." pseudodruryi in having a much more prominent thickened lip, more inflated and subglobular, and less wedge-shaped, chambers, a higher spire, and a more irregular, cap—like final chamber. Stratigraphic Range : "Globigerina1 1 nepenthoides occurs as rare specimens in sediments from the upper Catapsydrax dissimilis Zone and Globigerinatella insueta Zone at Site 237 only. "Globigerina" pseudodruryi (Bronnimann and Resig) Plate Figure 3 Globigerina pseudodruryi Bronnimann and Resig, 1971, PI. 7, Figs. 1, 2. Globigerina woodi Jenkins, Berggren and Amdurer, 1973, PI. 27, Figs. 5, 6? "Globigerina" p s eudo druryi (Bronnimann and Resig), Fleisher, 197^a, PI. 6, Fig. 10. Remarks: See comments above for "Globigerina” nepenthoides. 151 Stratigraphic Range; This species is present in the Catapsydrax dissimilis Zone at Site 237* and in the Globigerinatella insueta Zone at Sites 219 (part) and 237# "Globigerina" woodi connecta (Jenkins) Plate 4, Figures 1, 2 Globigerina woodi connecta Jenkins, 1964a, Fig* 1. Globigerina woodi connecta Jenkins, Jenkins, 1963b, PI* 17# Globigerina woodi connecta Jenkins, Jenkins, 1971* PI* 18, Figs. 343-347. Globigerina woodi connecta Jenkins, Berggren and Amdurer, 1973, PI* 27, Fig. 3. Remarks; The relationship of this form with Globigerinoides trilobus« its reported descendent (Jenkins, 1963b, 1971), is di scussed under the latter species. 1!G, " woodi connecta differs from the nominate subspecies in its much more compact test, more closely appressed chambers, and much lower and somewhat broader aperture. Stratigraphic Range: This species was observed only at Site 237* where it ranges from the Globoquadrina binaiensis Zone to the top of the Catapsydrax dissimilis Zone. 1 1 Globigerina1 1 woodi woodi (Jenkins) Globigerina woodi Jenkins, i960, PI. 2, Fig. 2. Globigerina woodi woodi Jenkins, Jenkins, 1963b, PI. 17* 132 Globigerina woodi woodi Jenkins, Jenkins, 1971, PI* 18, Figs. 548-550. Globigerina woodi Jenkins, Jenkins and Orr, 1972, PI. 11, Figs. 10—12. Globigerina woodi Jenkins, Berggren and Aradurer, PI. 27, Fig.4 only. Remarks: Tbe published records of this species sug gest that "G.” woodi woodi is primarily an extratropical species (see Blow, 19^9), although it occurs at Site 237 and in the eastern equatorial Pacific (Jenkins and Orr, 1972). Stratigraphic Range: ”G. 1 1 woodi woodi occurs as rare specimens throughout much of the interval from the Globoquadrina binaiensis Zone to the Globigerinatella in- sueta Zone at Site 237* Two isolated occurrences were ob served within the Globoquadrina binaiensis Zone at Site 220 as well. GENUS Globigerinatella Cushman and Stainforth, 1945 Type Species: Globigerinatella insueta Cushman and Stainforth. Remarks: Blow (1969) suggested that Globigerina tella evolved from Globigerinita ambitacrena. and inter mediate specimens whose morphology supports this conclusion were occasionally observed in lower Miocene sediments here. The wall texture of G. insueta, originally described by 153 Hofker (l95^» compare with Fleisher, 197^-a, PI* 9> Fig* 2), is also microperforate as in Globigerinita* The close relationship with Candeina suggested by Hofker (195^0 ap pears to represent parallel evolution of (very approximate) isomorphs from essentially the same ancestor* Globigerinatella insueta Cushman and Stainforth Globigerinatella insueta Cushman and Stainforth, 19^5* PI* 13, Figs. 7-9. Globigerinatella insueta Cushman and Stainforth, Bronnimann, 1950a, PI. 13, 14. Globigerinatella insueta Cushman and Stainforth, Blow, 1969, PI. 26, Figs. 1-7. Remarks: The patchy distribution of rare specimens of this form at Sites 219 and 237 suggests that G. insueta is moderately to strongly susceptible to test dissolution. Stratigraphic Range: Rare specimens were observed in the Catapsydrax dissimilis Zone at Site 237 and in the Globigerinatella insueta Zone at Sites 219 and 237. A single specimen noted in Sample 237-20-1, 79-81 cm, at the top of the "Turborotalia1 1 kugleri Zone, probably represents downhole contamination. t t GENUS Globigerinatheka Bronnimann, 1952 tt Type Species: Globigerinatheka barri Bronnimann. 15^ Synonym: Globi^erapsis Bolli, Loeblich, and Tappan, 1957* Guembelitrioides El-Naggar, 1971* Remarks: Globigerinatheka has recently been re examined in detail by Proto Decima and Bolli (1970) and Bolli (1972), who concluded that the bullae of Globigerap sis do not justify its separation at the generic level. That view is accepted here. Little can be added to their discussions concerning species distinction and relation ships within this complex group. Bolli*s (1972) reconstruction of the phylogenetic patterns is also tentatively accepted. One important un answered question, however, is the identity of the ances tral species. Bolli (1972) suggested that the evolution of this group began with G. subconglobata raicra, a form that has not been observed here. From published illustra tions (Bolli, 1972), Fleisher (197^3-) concluded that G. subconglobata micra probably evolved from Globigerinatheka sermi, presumably within the G. senni Zone. Proto Decima and Bolli (1970) amended Globigerinatheka to include only forms with multiple accessory apertures, but the above phylogenetic considerations suggest that G. senni should be included as well. Bolli (1972) treated the species placed in Globigerinatheka as representative of four basic species groups, with the morphotypes within each treated as sub- 155 species. Although most of these groups seem to comprise related forms, it does not necessarily follow that these forms should be differentiated only at the subspecies level. The taxa have thus been returned to species-level status, ti Globigerinatheka barri Bronnimann Globigerinatheka barri Bronnimann, 1952, Figs. 3a—c, g, h. Globigerinatheka barri Bronnimann, Bolli, Loeblich, and Tappan, 1957, PI. 7, Fig. 12. Globigerinatheka barri Bronnimann, Bolli, 1972, PI, 1, Figs. 18-21; PI. 2, Figs. 8-20; PI. 4, Figs. 1-6. Stratigraphic Range: G. barri occurs in the Truncorotaloides pseudodubius Zone at Site 219, and in the T. pseudodubius and Globigerinatheka semiinvolutus Zones at Site 237* Occasional individuals were also found in the Morozovella coronata — M. aragonensis Zone at all three sites. Globigerinatheka curryi Proto Decima and Bolli Plate 4, Figures 4, 5 Globigerinatheka curryi Proto Decima and Bolli, 1970, PI. 1, Figs. 1-4; PI. 3, Figs. 1, 2; Text figs. 1-3, 38-39. Globigerinatheka subconglobata curryi Proto Decima and .opigerinatneica supcongiopata curryi Bolli, Bolli, 1972, PI. 1, Fig. l4. Globigerinatheka subconglobata curryi Proto Decima and Bolli, Fleisher, 1974a, PI. 8, Fig. 8. 156 Remarks: Some difficulty may be encountered in distinguishing; this species from G. subconglobata* G. curryi differs in having a more compact and subspherical test form with a lower spire, less distinct chambers, and smaller and less circular apertures. In addition, the final chamber of G. subconglobata is typically flattened, whereas it is inflated in G. curryi. G. curryi is intermediate in overall test form be tween G. subconglobata and G. euganea; the basis for dif ferentiating it from the latter is discussed below. Stratigraphic Range: This species is found in the Globigerinatheka curryi - G. euganea Zone and the upper most portion of the Morozovella coronata — M. aragonensis Zone at Sites 219 and 237* Globigerinatheka euganea Proto Decima and Bolli Plate 4, Figures 9* 10, 11 Orbulinoides beckmanni (Saito), Samanta, 1970, PI. 2, Figs. 22, 23. Globigerinatheka euganea Proto Decima and Bolli, 1970, PI. 1, Figs. 6—11; PI. 3> Figs. 3-5; Text figs. 8-15, 31> ^3-^5. Globigerinatheka subconglobata euganea Proto Decima and Bolli, Bolli, 1972, Text figs~ 31-^24 Remarks; G. euganea differs from G. curryi in its more spherical test form and less deeply incised sutures, as well as its smaller sutural apertures. Although the two 157 species apparently intergrade completely (Proto Decima and Bolli, 1970), little difficulty was encountered in dif ferentiating them in most samples examined here. This species has been recorded on occasion as Qrbulinoides beckmanni because of its nearly spherical test shape (cf, Samanta, 1970)• Stratigraphic Range: G. euganea was found only in the G. curryi - G. euganea Zone at Site 237* Globigerinatheka higginsi (Bolli) » Plate 59 Figures 1, 2 "Globigerinoides1 1 higginsi Bolli, 1957c* FI* 3^, Figs. 11-13. Glob igerinoides higginsi Bolli, Raju, i960, PI. 2, Fig* 7* Globigerinatheka higginsi (Bolli), Fleisher, 1974a, PI. S, Fig. 4. Remarks: Bolli (l957c) originally placed this species in tfGlobigerinoides1 1 because of its secondary sutural apertures, although he realized that little likeli hood of a relationship existed between this Eocene form and the Neogene genus Globigerinoides. His objections to plac ing l!G. M higginsi in Globigerapsis (Globigerinatheka of this report)-—that it differed morphologically from G. index, the oldest known species of Globigerapsis— are not critical if phyletic criteria are assigned primary impor tance (Fleisher, 1974a). 138 The phylogenetic validity of this generic assign ment (i.e., Globigerinatheka higginsi).however. cannot at present be verified. Clearly this species should not be placed in Globigerinoides. but it is difficult to recog nize where it might fit into the reconstructed phylogeny °P Globigerinatheka spp. (Bolli, 1972). Conceivably it may be ancestral to G. rubriformis. but the question of the ancestor of G, higginsi remains unanswered. Because it is more difficult still to recognize another Eocene genus within which this species could be justifiably placed on both phyletic and morphologic grounds, the taxonomic com bination proposed by Fleisher (l97^a) is retained here. El-Naggar (1971) erected the genus Guembelitrioides for this species, but his taxon is based Lipon particularly arbitrary criteria and does not appear to be useful for morphologic, stratigraphic, or phyletic considerations. Stratigraphic Range: G. higginsi is rare but pre sent in all three sites. It is found only in the Globigerinatheka senni and Morozovella coronata - M. aragonensis Zones. Globigerinatheka index (Finlay) Globigerinoides index Finlay, 1939> PI* Figs. 83-88. Globigerinoides index Finlay, Hornibrook, 1938, PI. 1, Figs. 11 — 13 ("holotype reillustrated) , 159 Globigerinatheka index index (Finlay), Bolli, 1972, PI. 1, Figs. 1-4, 6, 7. Globigerinatheka index index (Finlay), Fleisher, 197^a, PI. 8, Fig. 6. Remarks; Bolli (1972) summarized the information which suggests that G. index was primarily a temperate- water species and survived longer in middle to high alti tude regions than in the tropics. The base of the range of this species, however, occurs earlier here than has been generally reported (Bolli, 1972), and some of the specimens here referred to G. index may instead be juvenile forms of G. subconglobata. Stratigraphic Range: This species first appears in the Globigerinatheka senni Zone at Site 220, and ranges as high as the G« curryi — G. euganea Zone at Site 237* Globigerinatheka kugleri (Bolli, Loeblich, and Tappan) Globigerapsis kugleri Bolli, Loeblich, and Tappan, 1957* PI. 6, Fig. 6. Globigerinatheka mexicana kugleri (Bolli, Loeblich, and Tappan), Bolli, 1972, PI. 2, Figs. 6, 7. Globigerinatheka mexicana kugleri (Bolli, Loeblich, and Tappan) , Fleisher, 197^-a, p. 1020. Remarks: As Bolli (1972) has noted, many of the older references to G. kugleri involved misidentifications of G. subconglobata. The illustration and description of 160 the latter has therefore greatly restricted the concept of kugleri (as employed here) to the characteristics dis cussed by Bolli (p. 128—129)* Stratigraphic Range: Isolated occurrences of single specimens were observed in the Morozovella coronata — M. aragonensis Zone at Site 220 and in the Globigerinatheka curryi — G. euganea and basal Truncorotaloides pseudodubius Zones at Site 237* Globigerinatheka luterbacheri Bolli Globigerinatheka subconglobata luterbacheri Bolli, 1972, PI. 1, Figs. 17, 22-25; PI. 7, Figs. 1-17* Globigerinatheka subconglobata luterbacheri Bolli, Fleisher, 197^a, p. 1021. Remarks: This form is quite similar to G. euganea. differing in its more deeply incised sutures and more common and variable bullae. Bolli (1972) suggested that it is primarily temperate in its distribution, a conclusion supported by its rarity at these sites. Stratigraphic Range: A single specimen in Sample 219-19-6, 51-53 cm, probably represents contamination, as this sample falls just below a significant unconformity. At Site 2379 G. luterbacheri is present in Sample 237—24—1, 79-81 cm, in the Globigerinatheka semiinvoluta Zone. 161 Globigerinatheka mexicana (Cushman) Globigerina mexicana Cushman, 1925a, PI. 1, Fig. 8. Globigerina mexicana Cushman, Blow and Saito, 1968, Figs. 1 - 4 (holotype reillustrated). Globigerinatheka mexicana mexicana (Cushman), Bolli, 1972, PI. 2, Figs. l-5l PI. Figs. 1-6. Globigerinatheka mexicana mexicana (Cushman), Fleisher, 1974a, PI. 8, Fig. 5. Remarks: Bolli*s (1972) reevaluation of this taxon is accepted here in full. Stratigraphic Range: Globigerinatheka mexicana first appears within the Morozovella coronata - M. aragonensis Zone at Sites 219 and 220, and ranges to the top of the Truncorotaloides pseudodubius Zone at Sites 219 and 237. Globigerinatheka rubriformis (Subbotina) Globigerinoides rubriformis Subbotina, 1953 (l97l)» FI* 13, Fig. 19; I>T~. l4, Figs. 6-9. Globigeinatheka index rubriformis (Subbotina), Bolli, 1972, PI. 1, Figs. 5, 11-13* Stratigraphic Range; Very rare and isolated speci mens were recovered at Site 237 from samples ranging from the Morozovella coronata - M. aragonensis to the Globigeri natheka semiinvoluta Zone. This species is nowhere common and Bolli*s interpretation of it as a temperate water form is probably justified. 162 G1 obiterinatlieka semiinvoluta (Keijzer) Globigerinoides semi-involutus Keijzer, 1945* PI* 4, Fig. 58. Globigerapsis semiinvoluta (Keijzer), Bolli, 1957c, PI. 36, Figs * 19, 20. Globigerapsis mexicana (Cushman), Raju, 1971* PI* H* Figs, 1-6. Globigerinatheka semiinvoluta (Keijzer), Bolli, 1972, PI. 5, Figs. 1-27; PI. 6, Figs. 1-17; Text Figs. 72-79. Globigerinatheka semiinvoluta (Keijzer), Fleisher, 1974a, p. 1021. Remarks: All of the specimens observed in these samples are small for this species, with few accessory apertures. Bolli (1972) has demonstrated that specimens of this sort (e.g., his Plate 5* Figs. 1—3* 7-9* 15-17) form a portion of typical G. semiinvoluta populations, but why the assemblages recovered here should be restricted to these forms is not clear. Stratigraphic Range: G. semiinvoluta ranges from just below the top of the Truncorotaloides pseudodubius Zone at Site 219 to the top of the G. semiinvoluta Zone. Globigerinatheka senni (Beckmann) Plate 5* Figures 4, 5 Sphaeroidine11a senni Beckmann, 1953* PI* 26, Figs. 2-4. Globigerina senni (Beckmann), Bolli, 1957c, PI. 35* Figs. 10-12. Globigerinatheka senni (Beckmann), Fleisher, 1974a, PI. 8, Figs. 10, 11. 163 Remarks: The thickened wall and highly compact test of G. senni suggest (Fleisher, 197^a) that it may be the ancestral species of Globigerinatheka, giving rise to G. micra in the late Early Eocene (G. senni Zone), The possibility remains that the similarity between the less elongate, more subspherical forms of G. senni (see Bolli, 1957c, PI. 35t Fig. 10) and typical G. micra may result from parallel evolution in response to similar environ mental stimuli rather than direct phyletic affinity. None theless, C. senni appears to be the most reasonable source species for the simplified forms of Globigerinatheka. and it has been interpreted here in this way. G. senni in turn appears to have been derived from Subbotina kiersteadae, a species which lacks the compact test and thickened wall of Globigerinatheka. Thus, in the series S. kiersteadae-G. senni—G. micra. the morphologic affinities of G. senni are closer to the descendent than to the ancestral species. Although G. senni lacks the secondary apertures which "define" Globigerinatheka (Proto Decima and Bolli, 1970), these features are apparently ab sent as well in G. micra. In view of these morphological relationships, it seems most appropriate to place this species in Globigerinatheka rather than in Subbotina. Stratigraphic Range: Globigerinatheka senni ranges from the base of the G. senni Zone (Site 220) to the top 16k of tlie Truncorotaloides pseudodubius Zone at Site 219 and into the G. semiinvoluta Zone at Site 237* Globi^erinatheka cf, G. senni Plate 5> Figures (T, 7 Remarks: These forms are generally similar to G. senni but differ slightly in their pattern of chamber ar rangement * The spire is lower than in typical G. senni, but the test appears elongate because of the dispropor tionate length of the chambers in the final whorl. As in G. senni, the development of granules is particularly prominent on the umbilical shoulders. The final chamber partially covers the umbilicus in many cases, however, and the aperture becomes narrow and frequently slitlike, rather than rounded. G. cf. G. senni is probably related to G* senni. but the nature of this relationship is unknown at present. Stratigraphic Range: Globigerinatheka cf. G. senni was observed only at Site 237» where it ranges from the lower part of the Globigerinatheka curryi — G. euganea Zone to within the G. semiinvoluta Zone. It disappears at the same horizon as G. senni, and is relatively common toward the upper end of its range. 165 Globigerinatheka subcon^lobata (Chalilov) Plate 4, Figures 6, 77 8 Globigerinoides subconglobatus var* subconglobatus Chalilov (rasein Shutskaya, 1958, PI. 1, Figs. 4-11. Globigerinatheka subconglobata subconglobata (Shutskaya) (sic). Bolli. 1972, PI. 1, Figs. 8-10, 15, 16. Globigerinatheka subconglobata subconglobata (Chalilov), Fleisher, 1974a, PI. 8, Fig. 9. Remarks: This is a Fairly generalized and long- ranging form which appears to have been cited until re cently as G. kugleri. The thick wall, large test size, and deeply incised sutures differentiate G. subconglobata from most other species in this genus; see, however, the comments above for G. curryi. Stratigraphic Range; This species ranges from just below the top of the Globigerinatheka senni Zone at Sites 220 and 237 to within the Morozovella coronata — M. aragonensis Zone at Sites 219 and 220 and the G. curryi - G. euganea Zone at Site 237* Globigerinatheka tropicalis (Blow and Banner) Globigerapsis tropicalis Blow and Banner, 1962, PI* 15» Figs. D, E, F. Globigerinatheka lindiensis Blow and Banner, 1962, PI. 13, Figs. 0, P, Q. Globigerinatheka index tropicalis (Blow and Banner), Bolli, 1972, PI. 3, Figs. 1-24; PI. 4, Figs. 7-12. 166 Stratigraphic Ran^e; G. tropicalis ranges from the Truncorotaloid.es pseudodubius Zone through the Globigeri natheka semiinvoluta Zone at Sites 219 and 237- GENUS Globigerinita Bronnimann, 1951 Type Species: Globigerinita naparimaensis Bronni mann . Synonymy: Tinophodella Loeblich and Tappan, 1957- Remarks: The morphologic basis for distinguishing Globigerinita from Catapsydrax has been discussed above. The differences in wall texture are easy to recognize in reflected light, and provide no practical difficulty. Phylogenetically as well, the two genera are quite distinct. The evolutionary history of Catapsydrax has al ready been described. The earliest species of Globigerin ita. G. boweni. evolved from the microperforate form Tenuitella clemenciae; this transition has been observed in New Zealand (Jenkins, 1966) and in these Indian Ocean samples. The wall texture and phyletic history distinguish these genera from all other Neogene forms, and if Tenui tella and Globigerinita are ultimately descended from a smooth-walled Early Paleocene form (e.g., Globigerina eugubina or G. aff. G. fringa of Krasheninnikov and Hos kins, 1973) unrelated to the Hedbergella monmouthensis - ?Subbotina pseudobulloides series (Berggren, 1962; Olsson, 167 1970), the phylogenetic separation of Globigerinita and Catapsydrax predates the base of the Cenozoic, As thus restricted, Globigerinita includes only those globigeriniform species with a microperforate wall* This test form/wall texture combination appears to have evolved only once, in the Late Oligocene. The umbilical bulla frequently used to characterize this genus is com monly but not universally present. Globigerinita boweni Bronnimann and Resig Plate 5* Figure 8 Globigerina .juvenilis Bolli, Jenkins, 1966, Fig* 15* Nos. 134-144. Globigerinita boweni Bronnimann and Resig, 1971* PI* 26, Figs. 1-4. 1 1 Globigerinita boweni Bronnimann and Resig, Fleisher, 197^a, PI. 9, Fig. 4. Remarks: This very small species seems to have been referred consistently to Globigerina .juvenilis Bolli, in part because the bulla is only infrequently developed or preserved. Jenkins (1966) observed the transition from a turborotaliid form, Globorotalia munda (= Tenuitella clemenciae of this report), to a globigerinid species, Globigerina .juvenilis (= Globigerinita clemenciae) , in strata approximately equivalent to the “Turborotalia” opima opima Zone. A similar transition has been observed here in the slightly younger Globoquadrina binaiensis Zone. 168 Strati graphic Range : Globigerinita boweni first appears within the Globoquadrina binaiensis Zone at Site 237, and ranges as high as the Globigerinatella insueta Zone at Site 219# Globigerinita glutinata ambitacrena (Loeblich and Tappan) Tinophodella ambitacrena Loeblich and Tappan, 1957b, Figs. 2, 3. Globigerinita glutinata (Egger), Parker, 1962, PI. 9* Figs, 7, 8, 9?, 13-15. Globigerinita glutinata glutinata (.Egger) , Bronnimann and Resig, 1971, PI. 23, Fig. 5# Globigerinita glutinata ambitacrena (Loeblich and Tappan), Fleisher, 1974a, PI. 9, Fig. 3. Remarks: The biological function and taxonomic significance of the presence and nature of bullae in Globigerinita glutinata is not understood, although it is clear from modern populations that bullae may be present on some members of the species assemblage and absent on others. In addition, examination of large populations from the Arabian Sea (Fleisher, 1974a) and Red Sea (Fleisher, 1974b) suggests that virtually complete inter- gradation exists between the simplest and the most com plex bullae. No subdivision of bullate populations, therefore, appears to be justified. The three subspecies of G. glutinata recognized 169 here are very probably no more than variants, but evidence from the Red Sea suggests that they may have different environmental tolerances and thus may be worth distinguish ing. G. glutinata ambitacrena is thus used for forms with either simple or digitate bullae. The holotype of G. naparimaensis incrusta Akers has been examined, and al though this form was not observed at these sites, G. incrusta is probably distinct from G. glutinata ambita— crena. Stratigraphic Range: This subspecies was recog nized in sediments from the "Turborotalia1 1 kugleri to Globigerinatella insueta Zones at Site 237# It was absent below Zone N.17 at Site 219# Because all forms of Globigerinita except G. boweni were absent in the Globi— gerinatella insueta Zone at Site 219, their absence is probably due to lack of preservation rather than original absence, Globigerinita glutinata glutinata (Egger) Globigerina glutinata Egger, 1893, PI# 13, Figs. 19-21. Globigerina .juvenilis Bolli, 1957^, PI. 24, Figs. 3, 6. Globigerinita glutinata .juvenilis (Bolli) , Bronnimann and Resig, 1971, Fig. 16. Globigerina .juvenilis Bolli, Jenkins and Orr, 1972, PI. 10, Figs. 1-3, not 4, 3* 170 Globigerinita glutinata glutinata (Egger), Fleisher, 197^&» PI. 9, Figs. 1, 2. Remarks: Most authors, some explicitly (e.g., Bronnimann and Resig, 1971» P* 1305; Jenkins and Orr, 1972, p. 1089) have used the species-rank name .juvenilis to represent Forms identical to Globigerinita glutinata (G. glutinata ambitacrena of this report)except in the ab sence of an umbilical bulla. And because the definition of Globigerinita has usually been taken to include the presence of an umbilical bulla, these forms have generally been placed in Globigerina. It is clear from examination of modern populations that the bullate and nonbullate forms are part of a single population, and that the presence of the bulla has onto genetic and probably ecologic, but not phyletic, signifi cance. The separation of these two forms into different genera is thus completely unjustified. The holotype of Globigerina juvenilis Bolli differs from modern nonbullate specimens of Globigerinita gluti nata s.l. only in showing a measure of dorso—ventral com pression. At present, the author considers Bolli*s form to fall within the population range of nonbullate G. glutinata. although intensive study of Early Miocene populations may show that it is different. Because the holotype chosen by Egger for Globigerina glutinata lacks a bulla, this species—rank name is used for the non—bullate 171 subspecies, and Q_. .juvenilis is treated as a junior synonym* Tiie microperforate wall distinguishes G. glutinata s*s* from other non—bullate globigeriniform species, but the chamber shape and arrangement shows considerable variation* Ignoring the surface texture may thus lead to serious taxonomic confusion* Krasheninnikov and Hoskins (1973), for instance, have assigned minor variants of G* glutinata to Globigerina bulbosa (PI. 6, Figs* 9-ll)9 Globigerina juvenilis (PI. 8, Fig. 6), Globigerina para- bulloides (PI. 9, Figs. 7-9), and Globigerina prae- bulloides (PI. 9, Fig. 10-12). Stratigraphic Range: This form ranges from the top of the Globoquadrina binaiensis to the Globigerina— tella insueta Zone at Site 237* At Site 219, it is not present below N.17. G1obigerinita glutinata parkerae (Bermudez) / Globigermoides parkerae Bermudez, 1961, PI. 10, Figs. 10, 11. Globigerinita glutinata (Egger), Parker, 1962, PI. 9, Figs. 2, 3, 5, 6, 11. Globigerinita glutinata flparkerae Bronnimann and Resig, 1971, PI. 23, Text fig. 13; PI. 23, Figs. 1-4; PI. 50, Fig. 6 (nom. nov.). ✓ Globigerinita glutinata parkerae (Bermudez), Fleisher, 1975a, p. 1022. 172 Remarks: Globigerinita glutinata flparkerae was pro posed (Bronnimann and Resig, 197l) as a replacement name for Globigerinoides parkerae« a species these authors con sidered to be a secondary junior homonym of Globigerinita parkerae Loeblich and Tappan. As the latter species is more correctly placed in Turborotalita, no homonymy exists and the replacement name should be treated as a junior objective synonym of Bermudez’s taxon (Fleisher, 197^a). Stratigraphic Range: A single occurrence was noted in Sample 237-19-5* 79—81 cm, within the Catapsydrax dissimilis Zone. Globigerinita uvula (Ehrenberg) Pylodexia uvula Ehrenberg, 1861, p. 276; 1873* PI* 2, Figs. 2k, 25* Globigerina bradyi Wiesner, 1931* P* 133* Globigerinoides minuta Natland, 1938, PI. 7* Figs. 2, 3* Globigerina bradyi Wiesner, Banner and Blow, 1960a, PI. 3, Figs. 1 (lectotype), 2. Globigerinita uvula (Ehrenberg), Fleisher, 197^a, p. 1022. Remarks: This species seems to have evolved in the Late Oligocene or Early Miocene from Globigerinita boweni, primarily by an increase in the height of the spire and in the number of chambers in the test. Both forms have k chambers per whorl, and G. boweni seems to be 173 the only likely ancestral species, Stratigraphic Range; G. uvula is present from the lower portion of the "Turborotalia” kugleri Zone through the Globigerinatella insueta Zone at Site 237- GENUS Globigerinoides Cushman, 1927 Type Species: Globigerina rubra dlOrbigny. Remarks: The origin and evolution of Globigeri noides remains a matter of considerable dispute. Blow and Banner (1962) proposed that the earliest known species, Globigerinoides primordius, evolved during the basal Miocene from Globigerina praebulloides occlusa and sub sequently gave rise to the other species assigned to this genus. Scott (1972) showed that the initial appearance of G. primordius occurred somewhat lower than Bloxv and Banner (1962) or Blow (1969) had realized. The morphologies of these two species support this potential lineage, although the similarity between them does not seem to be as strong as suggested. The entailed transition from a spinose to a cancellate wall is much less likely, however, and the wall textures of the transi tional specimens illustrated by Blow and Banner (1962) have not been studied. Jenkins (1965b) suggested another alternative, 17^ namely that the early species of Globigerinoides evolved from "Globigerina” woodi wood! and "G, M woodi connecta. The populations of Globigerinoides altiaperturus examined here consist of specimens all but identical with "G,* ' woodi s.s. except in the possession of a small secondary" aperture. This evolutionary sequence seems to be clearly recognizable, and Scott*s (l97l) conclusion that G, alti aperturus arose from G, primordius does not appear valid. Although Scott*s statistical techniques are presumably satisfactory, his association of species names with statistically recognizable populations is incorrect. The forms which he labelled "Globigerinoides altiaperturus1 * appear to have evolved from G, primordius, but they are not conspecific with Bolli1s holotype or the specimens as signed to G, altiaperturus here. It seems possible to recognize a number of sub lineages within Globigerinoides, although the early pat terns of each are poorly known and only tentatively sug gested here, G. altiaperturus arose directly from "G," woodi s,s. and is ancestral to the G. sub quadra tu s - G. obliquus sequence discussed by Cordey (1967). As sug gested by Jenkins (1965b), G, primordius probably arose from ’ ’ G, * ' woodi through the development of a secondary aperture and the compression of the primary one, Scott (1971) suggested that G, quadrilobatus and G. trilobus descended from G, primordius, and this conclusion may 175 prove to be correct. Alternatively, G. quadrilobatus im- maturus may have evolved independently from ! f G. " woodi connecta, and may be ancestral to the G. quadrilobatus — G. trilobus sequence. Xn this case, G. primordius repre sents an evolutionary cul-de-sac. The second possibility is favored here, from the evidence advanced by Jenkins (1965b), but neither is here considered to have been con clusively demonstrated. In either case, the two primary lineages within Globigerinoides are sufficiently distinct morphologically and phyletically to warrant their separa tion into different subgenera, but this step is not justi fied until the details of the G. quadrilobatus evolution ary history have been determined. Globigerinoides altiaperturus Bolli Plate 5, Figures 9, 10 Globigerinoides triloba altiapertura Bolli, 1957b, PI. 25, Figs. 7, 8. Globigerinoides quadrilobatus altiaperturus Bolli, Blow, 1969, p. 325. Globigerinoides trilobus altiapertura Bolli, Scott, 1971, PI. 2, Figs. 1-3, 10. Globigerinoides trilobus (Reuss), Krasheninnikov and Hos kins, 1973, PI. 15, Figs. 7-9, not 6. Globigerinoides aff. altiaperturus Bolli, Fleisher, 197^a, PI. 9, Figs. 5, 6. Remarks: The views held here on the evolutionary history of this species are essentially those of Jenkins 176 (1965b), and have been discussed above. Banner and Blow's (1965b) statement that "the chamber shape, coiling mode and wall surface and structure of G. quadrilobatus alti aperturus (Bolli) (sic) are so closely similar to those of G. quadrilobatus s,s, that there can be no doubt of its im mediate ancestry , . ." (p. Ill) is difficult to evaluate, in that these two forms are not strikingly similar. It is probable that these authors had not at that time con sidered the possibility that G, altiaperturus could have arisen from anything other than another species of Globigerinoides, Blow's subsequent (1969* 1970b) treat ment of this form as a subspecies of G, quadrilobatus indicates that he did not modify this earlier opinion, G. altiaperturus can be distinguished primarily by the circular primary aperture— a character shared by most of the subsequent forms in this sublineage— and circular to semicircular secondary aperture, which may be very small in primitive forms. The chambers are typically more close ly appressed than in the G, quadrilobatus group, and more wedge-shaped; the specimens illustrated by Krasheninnikov and Hoskins (1973) appear to be a slight variant in this regard, Stratigraphic Range: This species is found in the "Turborotalia" kugleri through Globigerinate11a insueta Zones at Site 237» and within the lower part of the G, in- 177 sueta Zone at Site 219. This range is in accord with ob servations by Bronnimann and Resig (l97l), but somewhat longer than recorded by Blow (1969). Globigerinoides diminutus Bolli Globigerinoides diminutus Bolli, 1957h, PI. 25, Fig. 11. Globigerinoides diminutus Bolli, Fleisher, 197^-a, p. 1023. Stratigraphic Range; Rare specimens of* G. diminutus were noted in the Catapsydrax dissimilis Zone at Site 237 and in the Globigerinatella insueta Zone at Site 219* Globigerinoides obliquus obliquus Bolli Globigerinoides obliquus Bolli, 1957h, PI. 25, Figs. 9, 10. Globigerinoides obliquus obliquus Bolli, Fleisher, 197^a, P. 1023. Remarks; Most of* the forms examined here show little of the compression in the final chamber that was illustrated on the holotype. Fleisher (l97^^) discussed the characters used to differentiate this form from G. obliquus extremus. Stratigraphic Range: Globigerinoides obliquus obliquus first appears in the upper portion of the "Turborotalia" kugleri Zone at Site 237, where it ranges through the Globigerinatella insueta Zone. At Site 219, it 178 is present only in the upper part of* the G. insue ta Zone* Globigerinoides praesicanus Bronnimann and Resig tt Globigerinoides sicanus praesicanus Bronnimann and Resig, 1971, PI. 10, Figs. 5, 6, 8. Globigerinoides sicanus s.l. de Stefani, Fleisher, 19jka., PI* 9, Fig. 10. Remarks: Despite the criteria suggested by Bronni mann and Resig (l97l)» the large subspherical species of Globigerinoides remain difficult to differentiate. From the Site 237 populations and a re-examination of Arabian Sea material, it appears that the bulk of specimens en countered in these samples should be referred to G. praesicanus in that the final chambers are not as embrac ing as those of G. sicanus, and are more globular, with more slitlike apertures, than those of G. pseudosellii. Stratigraphic Range: Globigerinoides praesicanus is present in the upper Catapsydrax dissimilis Zone at Site 2 37 and throughout the Globigerinatella insueta Zone at Site 219. The single specimen observed in Sample 237- 20-1, 79-81 cm. probably reflects downhole contamination. The range reported here is thus a bit shorter than sug gested by Bronnimann and Res ig (1971). 179 Globigerinoides primordius Blow and Banner Globigerinoides quadrilobatus primordius Blow and Banner, 1962, PI. 9» Figs. D, E, F; Text fig. 14. Globigerinoides quadrilobatus primordius Blow and Banner, Blow, 1969> PI# 20, Figs. 1, 5* 6. Globigerinoides trilobus primordius Blow and Banner, Scott, 1971, PI. 1, Figs. 4-8; PI. 2, Figs. 4-6. Remarks: The specimens observed at Site 237 agree well with, the holotype, as well as with those illustrated by Blow (1969) and Scott (l97l)* The phyletic and strati- graphic problems relating to the origin of G. primordius have been discussed above. Stratigraphic Range; This species was found only at Site 2379 where it ranges throughout the "Turborotalia1 1 kugleri and lower Catapsydrax dissimilis Zones. Globigerinoides quadrilobatus immaturns LeRoy Globigerinoides sacculiferus immatura LeRoy, 1939> PI# 3» Figs. 19, 20. Globigerinoides triloba immatura LeRoy, Bolli, 1957b, PI. 25, Figs. 3, 4. Globigerinoides quadrilobatus immaturus LeRoy, Blow, 1969* P. 325. Remarks: This subspecies is the first of the forms of G. quadrilobatus to appear, and presumably the most primitive phyletically. The morphology of these forms, 180 particularly that illustrated by Bolli (l957h, PI. 25, Fig. 3), supports Jenkins’s (1965b) suggestion that this sub species (included by Jenkins in G. trilobus) evolved directly from "G." woodi connecta. Stratigraphic Range: G. quadrilobatus immaturus first appears at Site 237 in the lower part of the f l Turborotalia1 1 kugleri Zone, and ranges through the Globigerinatella insueta Zone. Globigerinoides quadrilobatus quadrilobatus (d'Orbigny) Globigerina quadrilobata d ’Orbigny, PI, 9, Figs. 7-10. Globigerina quadrilobata d ’Orbigny, Banner and Blow, 1960b, PI. 4, Fig. 3 ("lec to type). Globigerinoides quadrilobatus quadrilobatus (d’Orbigny), Blow, 1969, P. 325. Stratigraphic Range: G. quadrilobatus s.s. is pre sent from the Catapsydrax dissimilis Zone at Site 237 through the Globigerinatella insueta Zone at Site 219. Globigerinoides quadrilobatus sacculifer (Brady) Globigerina sacculifera Brady, 1877, P* 533; 1884, PI. 80, Figs. 11-17. Globigerina sacculifera Brady, Banner and Blow, 1960b, PI. 5"^ Figs. 1, 2. Globigerinoides quadrilobatus sacculifer (Brady), Blow, 1969, P. 326. 181 Remarks: Recent evidence from the Red Sea (Meyer, 1973) and Atlantic Ocean (Hecht, 197^) suggests that the distinction between G. quadrilobatus s.s. and G. quadri lobatus sacculifer may merit recognition. These two forms may have somewhat different environmental tolerances, based on their distribution, although the nature of the controlling parameters is not known. Stratigraphic Range: This species was noted at all horizons above the Sample 237-20-2, 79-81 cm., in the upper part of the "Turborotalia" kugleri Zone. It was not ob served below Zone N.17 at Site 219* Globigerinoides aff. G. sicanus de Stefani Globigerinoides sicana de Stefani, 1952, p. 9. Globigerinoides sicanus de Stefani, Blow, 1969, PI* 3» Figs. 10, 11 (holotype reillustrated). Globigerinoides bispherica Todd, in Todd et al., 195^» PI* T] Figs. 1^ £. Remarks: See the discussion, above, for Globi gerinoides praesicanus, from which this species appears to / " have evolved by the expansion of the final chamber (Bron nimann and Resig, 197l)* The specimens referred to G. sicanus s.l. by Fleisher (l97^a) are more properly assign ed here to G. praesicanus. Stratigraphic Range: A single specimen in Sample 182 237-19-3* 79-81 cm. (Catapsydrax dissimilis Zone), seems to represent a natural (i.e., noncontamination) occurrence. Its absence above this horizon suggests that this species is probably relatively soluble at oceanic depths. This report would place the lower end of the range of G. sicanus below the N.7-N.8 boundary as recognized by Blow (1969), but Bronnimann and Resig (l97l) also reported G. sicanus in beds of N.6 (C^. dissimilis Zone) age. Globigerinoides subquadratus Bronnimann 11 Globigerinoides subquadratus Bronnimann, in Todd et al., 1955, PI. 1, Figs. 5, 8. Globigerinoides rubra (d*Orbigny), Bolli, 1957b, PI. 25* Figs. 12, 13. Globigerinoides subquadratus Bronnimann, Cordey, 1967* PI* 103, Figs. 1-4. Globigerinoides subquadratus Bronnimann, Fleisher, 1974a, p. 1024. Stratigraphic Range; G. subquadratus first appears in the upper portion of the "Turborotalia" kugleri Zone at Site 237* and ranges through the top of the Globigerina tella insueta Zone at Site 219* Globigerinoides trilobus (Reuss) Globigerina triloba Reuss, I85O, PI. 47, Fig* 11. Globigerinoides triloba triloba (Reuss), Bolli, 1957b* PI* 25, Fig. 2. 183 Remarks; This name has commonly been used for the concept here embodied in G. quadrilobatus s.s# In this report, G# trilobus is used for forms with large and some what embracing final chambers, as illustrated by Blow (1956). Stratigraphic Range: This species was not dis tinguished from G. quadrilobatus at Site 219. At Site 237* however, G. trilobus is consistently present from the upper portion of the "Turbo rot alia1 1 kugleri Zone through the Globigerinatella insueta Zone# GENUS Globoquadrina Finlay, 19^+7 Type Species: Globorotalia dehiscens (Chapman, Parr, and Collins)# Remarks: Globoquadrina consists in common usage of a group of species characterized by a primarily umbilical aperture,typically with well—developed and usually triangular apertural teeth or flaps# The species complex included here first developed in the Late Oligo- cene and was analyzed in some detail by Blow (1969)* P# 338-3^2). Fleisher (l97^a) discussed these sublineages and recognized, based upon the information provided by Blow, five separate phyletic sequences# These broadly similar 184 sets of* species, with recognizable morphological characters in common, can be traced to one of* two closely related ancestral forms* The entire species complex, therefore, was placed within Globoquadrina * with the sug gestion that after additional study it might prove de sirable to designate the sublineages as distinct sub- genera. Dr. X. Premoli Silva (personal communication) has cast considerable doubt upon the evolutionary validity of the suggested sublineages. The available phyletic evi dence and the morphologic similarity of these forms nevertheless suggest that all are derived from either G. galavisi or G. t ripartita. The genus Globoquadrina is therefore used in the sense adopted by Fleisher (l97^a), an interpretation which necessitates the inclusion of the G. tripartita to G. binaiensis bioseries recognized by Blow and Banner (1962) and Blow (1969)* Globoquadrina altispira (Cushman and Jarvis) Globigerina altispira Cushman and Jarvis, 193&, Pi* i> Figs. 13,1^; Globoquadrina altispira altispira (Cushman and Jarvis), Bolli, 1957b7 PI. 24, Figs. 7, 8. Globoquadrina altispira altispira (Cushman and Jarvis), Fleisher, 197^a» PI. 10, Fig. 1. Stratigraphic Range: G. altispira is consistently 185 present at Sites 219 and 237 above tbe middle of* the "Turborotalia1 1 lcugleri Zone. Globoquadrina baroemoenensis (LeRoy) Plate Figure U Globigerina baroemoenensis LeRoy, 1939> Pi* 6, Figs. 1, 2. Globoquadrina baroemoenensis (LeRoy), Blow, 1969* ^8, FigsT 57 87 Globoquadrina baroemoenensis (LeRoy), Fleisher, 197^a, p. 1024. Remarks: The specimens referred here to Globo quadrina baroemoenensis agree quite well with LeRoy1s holotype illustration and with at least one of the speci mens illustrated by Blow (PI. 28, Fig. 4). These are forms with four to four and one half chambers per whorl, with the final one or two chambers distinctly compressed. The umbilicus is open and umbilical teeth are well developed. The spire is relatively flat, but in large forms the final chambers may be raised somewhat above the level of the spiral side. The specimens illustrated as G. baroemoenensis by Berggren and Amdurer (l973> PI* 26, Figs. 3» *0 are mis— identified. Their illustrated specimen has only three and one half chambers in the final whorl and shows no evidence of chamber compression or umbilical teeth. It is prob ably related to G. tripartita, or possibly to G. praede— hiscens. 186 The morphology of these forms suggests that G, baro emoenensis evolved from G. globularls by compression of the final chambers, rather than directly from G. galavisi as suggested by Blow (1969). G. globularis was reported to originate within Zone P. 21 (Blow, 1969)9 but it has been seen here and in the North Atlantic at horizons equivalent to late P. 19, prior to the first appearance of G. baro emoenensis, It is also possible that Blow1s "phylogeneti cally primitive" specimen of G. baroemoenensis (Pig, 8) should be referred to G. globularis. Stratigraphic Range: Only a single specimen, in Sample 219—13—2, 46—48 cm, Globigerinatella insueta Zone, was observed in the Arabian Sea, At Site 2379 however, it first appears near the top of the "Turborotalia” kugleri Zone and is present into the Globigerinatella in sueta Zone, Globoquadrina binaiensis (Koch) Globigerina aspera Koch, non Ehrenberg, 1926, Figs, 22, 23* Globigerina binaiensis Koch, 19359 P* 558, nom. nov, Globigerina binaiensis Koch, Blow, 1969f PI. 13t Figs, 1, 2. Stratigraphic Range: At Site 2199 very rare and isolated occurrences were noted within the Globigerinatella insueta Zone, These are probably reworked, in view of the 187 inconsistency of their appearance and the published range (Blow, 1969) of this species. At Sites 220 and 237* G. binaiensis occurs sporadically within the Globoquadrina binaiensis Zone; at the latter, it ranges as high as the basal sediments of the Catapsydrax dissimilis Zone. Globiquadrina dehiscens (Chapman, Parr, and Collins) Globorotalia dehiscens Chapman, Parr, and Collins, 19349 PI. 11, Fig. 3 6 . Globoquadrina dehiscens dehiscens (Chapman, Parr, and Collins), Blow, 1969* PI* 28, Fig. 1. Globoquadrina dehiscens dehiscens (Chapman, Parr, and Collins), Fleisher, 1974a, P* 1024-1025* Remarks: No distinction has been made here be- y' tween G. dehiscens s.s. and G, dehiscens advena Bermudez. Stratigraphic Range: G. dehiscens first appears near the base of the "Turborotalia” kugleri Zone at Site 237t and ranges through the Globigerinatella insueta Zone at Site 219* Globoquadrina praedehiscens Blow and Banner Globoquadrina dehiscens praedehiscens Blow and Banner, 1962, PI. 15, Figs. Q, R, S. Globoquadrina dehiscens praedehiscens Blow and Banner, Blow, 1969, PI. 29, Figs. 3-5. Globoquadrina praedehiscens Blow and Banner, Berggren and Amdurer, 1973* PI. 26, Figs. 13-15. 188 Stratigraphic Range: At Sites 220 and 237* G> praedehiscens ranges throughout the Globoquadrina binaien sis Zone, and occurs as high as the basal Catapsydrax dis similis Zone. Scattered occurrences were noticed in the Globigerinatella insueta Zone at Site 219, a range some what higher than that reported by Blow (1969) for this form. Globoquadrina galavisi (Bermudez) / Globigerina galavisi Bermudez, 1961, PI. b9 Fig. 3* Globigerina yeguaensis yeguaensis Weinzierl and Applin, Blow and Banner, 19^2, PI. 13, Figs. H, J, K, L, M. Globigerina galavisi Bermudez, Blow, 1969, PI# 5, Figs. 1—3 (holotype reillustrated)• Globoquadrina galavisi (Bermudez), Fleisher, PI. 10, Fig. 3. Remarks; Most workers have accepted Blow’s (1969) contention that the holotypes of G. galavisi and Globiger ina yeguaensis Weinzierl and Applin represent different species. Stainforth (197^0 re—emphasized the similarity of these two forms and suggested that they are conspecific. G. galavisi appears from the illustrations cited above to be more compact, with more closely appressed chambers. Pending a careful study of topotype populations, Blow’s differentiation is maintained here. Stratigraphic Range: At Sites 219 and 237, Globo- 189 quadrina galavis! appears at the base of the Truncoro- taloides pseudodubius Zone* Xt was also observed in Sample 237—25—1, 79-81 cm, the highest sampled horizon of the Globigerinatheka curryi - G. euganea Zone, but because an unconformity overlies this sample this occurrence probably reflects downhole contamination. The species ranges to the base of the Globoquadrina binaiensis Zone at Site 237, and scattered occurrences were noted within that zone at Site 220. Globoquadrina globosa Bolli Globoquadrina altispira globosa Bolli, 1957t>, Pl« 24, Figs. 9, 10. Remarks; This rarely-occurring form differs from G. altispira in having fewer chambers per whorl arranged in a much lower spire, and in lacking the distinctly com pressed chambers typical of that species. G. globosa. like G. altispira. probably evolved from G. globularis (Blow, 1969), but there seems to be no reason to treat them as subspecies of G. altispira. Stratigraphic Range: Globoquadrina globosa first appears at the base of the Catapsydrax dissimilis Zone at Site 237 and ranges through the basal Globigerinatella in- sueta Zone, Xt is consistently rather rare, and its ab sence at Site 219 is probably the result of dissolution. 190 Very rare and isolated specimens were noted at a few horizons in the Globoquadrina binaiensis Zone at Site 220. ✓ Globoquadrina globularis Bermudez Plate 6, Figure 1 Globoquadrina globularis Bermudez, 1961, PI. 13, Figs. 4-6. Globoquadrina altispira globularis Bermudez, Blow, 1969* PX. 28, Figs. X, 2 (?). / Globoquadrina globularis Bermudez, Berggren and Amdurer, 1973, PI. 26, Figs. 5-12. Remarks: The specimens noted at Site 237 correspond / well to Bermudez’s holotype, as well as to the forms il lustrated by Berggren and Amdurer (1973). G. globularis differs from G. galavisi, from which it seems to have evolved, in its larger and more open umbilicus and well- developed triangular apertural teeth. Xt seems to be ancestral to the other species of Globoquadrina character ized by these features, including G. altispira and G. globosa. Blow’s (1969) illustrated specimens are probably conspecific with those observed here, but because his SEM photographs are oblique it is difficult to be certain. Stratigraphic Range: Globoquadrina globularis was observed only at Site 237» where it ranges from the “Turborotalia1 1 opima opima Zone to the basal sample of the Catapsydrax dissimilis Zone. Berggren and Amdurer (1973) 191 suggested that it may be characteristic of the Late Oligocene, but their data indicate, as does the evidence from Site 237* that this species ranges into the Early Miocene in sediments equivalent to Zone N.4. Globoquadrina larmeui obesa Akers Globoquadrina obesa Akers, 1955* PI* 65* Fig* 5* Globoquadrina larmeui obesa Akers, Blow, 1969* PI* Figs. 7, 9* Globoquadrina larmeui obesa Akers, Fleisher, 197^a, p. 1025. Stratigraphic Range: This species is present in a number of samples from the Globigerinatella insueta Zone at Site 219* It was not observed elsewhere. Globoquadrina pozonensis Blow Plate 6, Figures 2, 3 Globoquadrina pozonensis Blow, 1959* PI* 10, Figs. 5^-56. Remarks; This small species has not been widely reported. Blow (1969) concluded that G. pozonensis repre sents only "an early arrested ontogenetic stage in the development of G. altispira globosa," but it is not clear what he meant. At Site 237 G* pozonensis is common to abundant in samples where G. globosa is completely ab sent, over a relatively significant interval in the Late Oligocene and Early Miocene. It is also absent in the 192 samples containing G. globosa, G. pozonensis differs from G. globosa, as suggested by Blow (1959)* in being consistently smaller and in having fewer chambers per whorl (typically four to five, as op posed to five or six in G. globosa), smaller but still distinct umbilical teeth, and in many specimens a lateral ly directed (in part) and slightly extra-umbilical aperture• Stratigraphic Range: G. pozonensis ranges at Site 237 from the middle of the Globoquadrina binaiensis Zone to the upper portion of the "Turborotalia1 1 kugleri Zone. This level is much lower than the Middle Miocene range (Blow, 1959) in Venezuela. Globoquadrina pseudovenezuelana (Blow and Banner) Globigerina veguaensis pseudovenezuelana Blow and Banner, 1962, PI. 11, Figs. J, K, L, N, 0. Globigerina p s eudovene zuelana Blow and Banner, Blow, 19^9 > PI. 19> Figs. 1, 2. Globoquadrina p s eudovene zuelana (Blow and Banner), Fleisher, 197^-a, 102 5. Remarks; This form appears to have evolved from G. galavisi in the Middle Eocene, but the morphological transition was not observed here. Stratigraphic Range: A single specimen was ob- 193 served within the Cassigerinella chipolensis — Pseudo- ha stigerina barbadoensis at Site 219* At Site 237* G* pseudovenezuelana ranges from the base of the Truncoro- taloides pseudodubius Zone to the top of the Turborotalia cerroazulensis Zone* Globoquadrina sellii Borsetti Globoquadrina sellii Borsetti, 1959* PI* 1* Figs. 3* Globigerina clarae Bermudez, 1961, PI. 2, Fig. 4. Globigerina oligocaenica Blow and Banner, 1962, PI. IO, Figs. G, L, M, N. Globigerina sellii (Borsetti), Blow, 1969* PI* 19* Figs. 4-6. Globigerina sastrii Raju, 1971* PI* 4, Figs. 1, 2. Globoquadrina sellii Borsetti, Fleisher, 1974a, p. 1023. Remarks: Specimens similar to the holotype of Globigerina sastrii Raju were occasionally encountered in association with G. sellii at Site 237* When the final embracing chamber of G. sastrii is removed, the two forms are identical, and Raju (l97l) reported their ranges as being the same. As a result, G. sastrii is here treated as a gerontic form of G. sellii. Stratigraphic Range: Globoquadrina sellii ranges from the "Turborotaliaf l opima opima Zone through the upper part of the "T." kugleri Zone at Site 237 and is present 194 throughout much of the Globoquadrina binaiensis Zone at Site 220. Globoquadrina tapuriensis (Blow and Banner) Globigerina tripartita tapuriensis Blow and Banner, 1962, PI. 10, Figs. H, J, K. Globoquadrina tripartita tapuriensis (Blow and Banner), Fleisher, 197^a, PI. 10, Fig. 4. Remarks: Blow and Banner (1962) discussed the ways in which this form can be distinguished from G. tripartita, which it most closely resembles. It evolved from G* tri partita near the base of the Oligocene. The scarcity of this species in samples of the appropriate age from Site 219 suggests that it is strongly susceptible to solution, more so at least than G. tripartita, which is present in this interval. Primary (i.e., biologic rather than de— positional) environmental control cannot be precluded, however, as a cause for this scarcity. Stratigraphic Range: Rare specimens were found in a few samples from the Cassigerinella chipolensis — Pseudohastigerina barbadoensis Zone at Site 219# It was absent at the other sites. Globoquadrina tripartita (Koch) Globigerina bulloides tripartita Koch, 1926, Fig. 21. 195 Globigerina rohri Bolli, 1957h, PI. 23, Figs. 1-4. Globigerina tripartita tripartita Koch, Blow and Banner, 1962, PI. 10, Figs. A’ B, C (holotype reillustrated), D, E, F. Globoquadrina tripartita tripartita (Koch), Fleisher, 1974a, p. 1023. Stratigraphic Range; G. tripartita first appears within the Truncorotaloides pseudodubius Zone at Sites 219 and 237 and ranges through the basal sediments of the Catapsydrax dissimilis Zone at the latter. Xt is present only within the Globoquadrina binaiensis Zone at Site 220. Globoquadrina venezuelana (Hedberg) Globigerina venezuelana Hedberg, 1937* PI. 92, Fig. 7. Globoquadrina vene zuelana (Hedberg), Parker, 1967, PI. 26, Figs. 4-10. Globigerina venezuelana Hedberg, Blow, 1969, p. 322. Remarks: Blow (1969) recognized the presence of "small umbilical, triangular—shaped teeth-like projections" in this species, and believed that it arose from G. globularis or some related form. Because of this morph ology and phyletic history, as well as the cancellate non- spinose wall, this form should be placed in Globoquadrina rather than Globigerina. Stratigraphic Range: This species first appears near the top of the Globoquadrina binaiensis Zone at Sites 196 220 (where it is particularly rare) and 237» and ranges through, the Globigerinatella insueta Zone at Site 219. GENUS Globorotalia Cushman, 1927 Type Species: Pulvinulina menardii var. tumida Brady. Remarks: The generic name Globorotalia has common ly been applied to all Tertiary planktonic foraminiferal species characterized by trochospiral coiling and an extra—umbilical aperture, particularly if these species also possess a peripheral keel or imperforate margin* This total reliance upon criteria of gross test morphology has resulted, as with Globigerina. in a taxon with little or no phylogenetic significance. This name is restricted here to the complex of finely perforate species which first appeared during the radiation of the Early and Middle Miocene. The transi tion from cancellate to finely perforate wall texture occurred within the evolution of Globorotalia (Fohsella) peripheroronda. which is thus recognized as ancestral to this group. G. (F*) peripheroronda gave rise to the G. (£•) fo^si bioseries (Blow and Banner, 1966), all of which are characterized by a finely perforate wall tex ture, and probably to Globorotalia (Hirsute11a) prae- scitula. which has been recognized (Blow, 1969) as ances- 197 tral to the remainder of the finely perforate species in cluded here* Thus, as redefined on the basis of wall texture and reconstructed phylogeny, Globorotalia includes only those Neogene species with a finely perforate wall. All of these, additionally, are characterized by an extra- umbilical aperture typically bordered by a flap—like lip, but these characters are present on species assigned to other genera as well. Excluded by this generic defini tion, however, are the Paleogene species with finely perforate (Globanomalina) or pseudospinose (Acarinina. Morozovella) walls, as well as the longer-ranging sequences characterized by cancellate (Turborotalia. "Tur- borotalia. 1 1 Neogloboquadrina) or microperforate (Tenuitel- la) surface textures. These species groups, all of which have typically been included in Globorotalia purely on the basis of apertural position, are distinguishable on the basis of considerations of phylogeny and (except for Globanomalina) of wall texture. Fleisher (l97^a) has discussed in detail the taxonomic problems associated with this group, as well as the subgeneric categories applied to the currently recog nized sublineages (Bandy, 1972). SUBGENUS Fohsella Bandy, 1972 Type Species; Globorotalia (Globorotalia) prae- 198 folis! Blow and Banner Remarks: The evolution of tliis bioseries, which culminated with G. (F. ) folisi s*l*, has been discussed by a number of authors (Blow and Banner, 1966; Olsson, 1971 * 1972), Bandy (1972) restricted G. (Foiisella) to sharp- edged and keeled forms, but from a phyletic standpoint the inclusion of G. (F.) peripheroronda is justified. Globorotalia (Fohsella) peripheroronda Blow and Banner Globorotalia (Turborotalia) peripheroronda Blow and Banner, 1966, PI. 1, Fig. 1; PI. 2, Figs. 1-3. Globorotalia (Fohsella) peripheroronda Blow and Banner, Fleisher, 197^a, PI. 10, Figs. 7, 8. Stratigraphic Range: Typical specimens of G. (F.) peripheroronda were found only within the Globigerinatella insueta Zone at Site 219* Globorotalia (Fohsella) aff. G. (F.) peripheroronda Blow and Banner Remarks: Jenkins (1967) suggested that G. (F.) peripheroronda (cited as Globorotalia mayeri barisanensis) may have evolved from Globorotalia (= "Turborotalia”) bella during the Early Miocene. Arguing against this pro posed bioseries is the presence of only four and one-half 199 to five chambers per whorl in "T.” bella, as opposed to five to six in G . (F.) peripheroronda. Furthermore, the dorsal intercameral sutures are nearly straight in the Former, and strongly recurved in the latter species. In contrast, the Forms cited here as G. (F.) aFF. G. (F.) peripheroronda diFFer From G. (F.) peripheroronda s.s. in possessing a somewhat larger umbilicus and more chambers per whorl (six and one—halF to seven). These specimens are intermediate between "Turborotalia” kugleri and G. (F.) peripheroronda s. s., and support the conclusion (Fleisher, 197^-a) that the latter evolved From the Former. Stratigraphic Range; G. (F.) aFF. G. (F.) peri pheroronda occurred, as rare specimens, only in the upper part oF the Catapsydrax dissimilis Zone at Site 237* SUBGENUS Globorotalia Cushman, 1927 Type Species: Pulvinulina menardii var. tumida Brady. Synonym: Menardella Bandy, 1972. Remarks: See Bandy (1972) and Fleisher (l97^a) For a discussion oF this subgenus. 200 Globorotalia (Globorotalia) archeomenardii Bolli Globorotalia archeomenardii Bolli, 1957b, PI, 28, Fig, 11. Globorotalia (Globorotalia) archeomenardii Bolli, Fleisher, 1974a, p. 1026. Stratigraphic Range; Very rare specimens of this species were observed in Sample 219-13-2, 46—48 cm, from the upper Globigerinatella insueta Zone. SUBGENUS Hirsutella Bandy, 1972 Type Species: Rotalina hirsuta d'Orbigny. Remarks: See Blow (1969) and Fleisher (1974a) for a discussion of the species included within this subgenus. Globorotalia (Hirsutella) praehirsuta Blow Globorotalia scitula praescitula Blow, 1959* PI# 19* Fig. 128. Globorotalia (Turborotalia) scitula praescitula Blow, Blow, 1969, PI. ^ FigsT 21-23 [Tiolotype re-illustrated); PI. 39, Fig. 9. Globorotalia (Hirsutella) scitula praescitula Blow, Fleisher, 1974a, PI. 12, Figs. 7, 8. Remarks: The New Zealand form referred to this taxon (Jenkins, 1971) has a distinct comma-shaped aperture similar to that shown on the original, but not the sub sequent, illustration of the holotype. Xt appears to be 201 different from Blow's subspecies. Stratigraphic Range: G. (H.) praescitula is limited to the Globigerinatella insueta Zone at Site 219# GENUS Globorotaloides Bolli, 1957 Type Species: Globorotaloides variabilis Bolli. Remarks: Globorotaloides is distinguished in morphologic terms on the basis of its ontogenetic change from extra—umbilical to umbilical apertural position. This may be difficult to determine from adult specimens, how ever, particularly because the recognized Paleogene species typically develop an umbilical bulla similar to that of Cat ap sydrax. Globorotaloides suteri Bolli Globorotaloides suteri Bolli, 1957b, PI. 27, Figs* 9—13* Globorotaloides suteri Bolli, Fleisher, 197^a, PI. 13* Fig. 7. Remarks: G. suteri is quite similar in form to Cat ap sydrax unicavus. from which it is distinguished here (in adult specimens) by the strikingly flat spiral side. Stratigraphic Range: Globorotaloides suteri ranges from within the Truncorotaloides pseudodubius Zone at Sites 202 219 and 237 to within the Globigerinatella insueta Zone at Site 219# Its consistent presence within this interval, even in the heavily dissolved sequences at Site 220, testify to its resistance to dissolution. Globorotaloides turgidus (Finlay) Globigerina linaperta turgida Finlay, 1939* P* 123* Globoro taloides turgida (Finlay), Jenkins, 1964b, PI. 7, Figs. 1-10; PI. 8, Figs. 1-12, 13 (holotype re illustrated) . Globorotaloides turgidus (Finlay), Fleisher, 1974a, PI. 13, Fig. 8. Remarks: This is the earliest known species of Globorotaloides, and may be distinguished from the similar G. suteri by its more distinct chambers and more inflated bulla. Stratigraphic Range: This species first appears within the Morozovella formosa — M. aragonensis Zone at Site 220, and ranges to within the Globigerinatheka curryi - G. euganea Zone at Site 237* GENUS Hantkenina Cushman, 192 3 Type Species: Hantkenina alabamensis Cushman. Remarks; Blow and Banner (1962) suggested the evolution of Hantkenina from Pseudohastigerina, presumably 203 In the early Middle Eocene, with, a second iterative development (H. primitiva) in the Late Eocene. The plani— spiral chamber arrangement supports this interpretation. The similarity in wall texture, morphology, and age of the earliest representatives of Hantkenina and Clavigerinella suggests that these two genera may also be very closely related. All species of Hantkenina observed in these samples were represented only by very rare and broken specimens. This genus, apparently, is highly susceptible to test dissolution, and its stratigraphic value in deep-sea sedi ments is accordingly reduced. SUBGENUS Cribrohantkenina Thalmann, 19^2 Type Species: Hantkenina (Cribrohantkenina) ber- mudezi Thalmann (= junior synonym of Hantkenina inflata Howe)• Remarks; Whether the development of a cribrate aperture in the late ontogenetic stages of this species (Blow and Banner, 1 9 6 2) warrants even subgeneric distinc tion is open to question. Pending further evaluation of these forms, and in view of the different reports of the range of H. (c^.) inflata (e.g., Beckmann et al., 1969; Postuma, 197l) 9 Hantkenina and Cribrohantkenina have been distinguished at this taxonomic level. 20b Hantkenina (Cribrohantkenina) inflata Howe Hantkenina inflata Howe, 1928, PI* 14, Pig* 2. Hantkenina mccordi Howe and Wallace, 1932, PI* 10, Fig* 1* Hantkenina danviliensis Howe and Wallace, 193^-» PI# 5* Figs. ik, 17* Hantkenina (Cribrohantkenina) bermudezi Thalmann, 19^2, PI. 1, Figs. 5, 6. Cribrohantkenina danviliensis (Howe and Wallace), Blow and Banner, 1962, PI. 16, Figs. G, H. Stratigraphic Range; Single specimens of H. (C^* ) inflata were found in Samples 219—17— 31—53 cm, and 237-23—2, 79-81 cm, both within the Turborotalia cerro- azulensis Zone. SUBGENUS Hantkenina Cushman, 192 3 Type Species: Hantkenina alabamensis Cushman. Synonymy: Aragonella Thalmann, 19^2. Applinella Thalmann, 19^2. Hantkeninella Bronnimann, 1950. Hantkenina alabamensis Cushman, 1925* PI# lf Figs# 1-6; PI. 2, Fig. 3; PI# 3, Fig. 1. Hantkenina (Hantkenina) alabamensis Cushman, Bronnimann, 1950b, PI. 36, Figs. 10, 1^-16. Stratigraphic Range; Very rare specimens were noted in isolated occurrences at Sites 219 and 237 from 205 the Truncorotaloides pseudodubius Zone to the Turborotalia cerroazulensis Zone, A single specimen in Sample 219-16-3» 32-34 cm (Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone) is probably reworked; another, in Sample 237-27-5* 79-81 cm (Morozovella coronata - M. aragonensis Zone) may represent contamination, Hantkenina (Hantkenina) aragonensis Nuttall Plate 7, Figures 1, 2 Hantkenina mexicana aragonensis Nuttall, 1930* Pi* 24, Figs. 1-3. Hantkenina aragonensis Nuttall, Postuma, 1971* p. 222, 223. Hantkenina (Hantkenina) mexicana aragonensis Nuttall, Fleisher, 1974a, p. 1029. Remarks: This species is distinguished from the very similar H. (H.) mexicana by the produced and somewhat tapering chamber extensions leading to the tubulospines. The chambers are blunter and less elongate in H. (H.) mexicana. In any case, these forms are sufficiently rare (because of test dissolution) and difficult to identify to preclude their use in detailed biostratigraphic interpre tation in deep-sea sediments. Stratigraphic Range; Very rare and isolated occur rences of broken specimens of H. (H,) aragonensis were observed within the Morozovella coronata - M. aragonensis Zone at all three sites. At Site 220, it is also present 206 in the uppermost sample assigned to the Globigerinatheka senni Zone* Hantkenina (Hantkenina) dumblei Weinzierl and Applin Hantkenina dumblei Weinzierl and Applin, 1929, PI* 43, Fig* 5* Hantkenina (Applinella) dumblei Weinzierl and Applin, Bronnimann, 1950b, PI. 55, Figs. 17, 18, 22-24; PI. 56, Fig. 5* Hantkenina dumblei Weinzierl and Applin, Postuma, 1971, p . 222- 223. Stratigraphic Range: Isolated occurrences of H. (H. ) dumblei were noted in the upper part of* the Morozovella coronata — M. aragonensis Zone at Site 237* Hantkenina (Hantkenina) longispina Cushman Hantkenina longispina Cushman, 19251>, PI* 2, Fig. 4. Hantkenina (Applinella) longispina Cushman, Bronnimann, 1950b, PI. 55, Figs. 11-13, 15, 16. Stratigraphic Range: H. (H.) longispina was found as isolated specimens in the upper part of the Morozovella coronata - M. aragonensis Zone at Site 237. 207 Hantkenina (Hantkenina) mexicana Cushman Hantkenina mexicana Cushman, 192 5b, PI. 2, Fig. 2, Hantkenina (Aragonella) mexicana Cushman, Bronnimann, 1950b, PI. 55, Figs. 1-6. Hantkenina mexicana Cushman, Samanta, 1973, PI. 7, Figs. 16-17. Hantkenina mexicana Cushman, Postuma, 1971, p. 222—223* Remarks: See the discussion for H. (H.) aragonen sis . above. Stratigraphic Range: This species is present as very rare broken specimens only within the Morozovella coronata - M. aragonensis Zone at Sites 219 and 237. GENUS Morozovella McGowran, in Luterbacher, 1964 Type Species; Pulvinulina velascoensis Cushman. Remarks: The groups of species included in the concept of Morozovella recognized here have typically been included in Globorotalia (see above), but should be dis tinguished from this Neogene genus on both morphological and phylogenetic grounds. All have a pseudospinose wall and in particular a keel composed of coalesced pseudo spines, in contrast to the finely perforate wall of Globorotalia and Globanomalina. Equally important, the morozovellids became extinct near the top of the Middle 208 Eocene, and tlie first Globoro talia evolved in the Early Miocene. Nevertheless, within this context Morozovella is employed very much as a form genus for species with an im perforate pseudospinose carina, Pseudospinose forms lack ing this feature have been placed in Acarinina, as have a few carinate species whose affinities with acarininids rather than morozovellids are relatively conclusive. Ultimately, the Paleogene species should be re organized into genera that reflect their phylogenetic histories. The few attempts to recognize discrete lineages— Luterbacher (1964), Berggren (1968), McGowran, 1968)-—are neither sufficiently complete nor sufficiently compelling to warrant such a reorganization at present. Morozovella aragonensis (Nuttall) Globorotalia aragonensis Nuttall, 1930» PI# 24, Figs. 6-8. Globorotalia aragonensis Nuttall, Luterbacher, 1964, Figs. 121-126. Morozovella aragonensis aragonensis (Nuttall), Fleisher, 197^a, PI. 14, Fig. 1. Stratigraphic Range: This distinctive and solution- resistant species ranges from within the Morozovella formosa- M. aragonensis Zone at Site 220 to the top of the M. coronata - M. aragonensis Zone at Sites 219 and 237# 209 Morozovella bandy! Fleisher Globorotalia spinulosa Cushman, van Heerden, 1970> PI# 1> Figs. 1, 2. Morozovella bandyi Fleisher, 197^-a, PI. 14, Figs. 3-8. Remarks; Fleisher (l97^a) noted the Flaring chambers, delicate keel, and dorsal accessory sutural apertures which characterize this species, and little needs to be added to that description. These accessory apertures, as well as the open umbilicus, serve to dif ferentiate M. bandyi from M. spinulosa (see below). A measure of variation can be observed in comparing early (Globigerinatheka senni Zone) specimens with younger forms as typified by the holotype. The phyletically primitive forms are characterized by a more "compact" test; that is, there is somewhat less flare to the chambers, which are also higher ventrally. The keel is inconsistent ly developed and less delicate, and the umbilicus is more open than in typical forms. The transition between these morphotypes can be observed at Site 237# Stratigraphic Range; M. bandyi ranges from within (Site 237) or near the top (Site 220) of the Globigerina— theka senni Zone, and disappears within the Globigerina— theka curryi - G. euganea Zone at Site 219 (in the type sample, 219—19—6, 31—53 cm) and near the top of the Morozovella coronata — M. aragonensis Zone at Site 237* 210 Morozovella caucasica (Glaessner) Plate 7> Figures 3, 4, 3 Globorotalia aragonensis caucasica Glaessner, 1937* FI. 1, Figs. 6. Globorotalia caucasica Glaessner, Luterbacher, 1964, Fig. 97. Morozovella aragonensis caucasica (Glaessner), Fleisher, 1974a, PI. l47 Fig. 2. Remarks: The concept of M. caucasica applied here is that expressed by Luterbacher (1964, Fig. 97)> al though an almost complete intergradation appears to exist between forms of this sort and typical M. aragonensis. The two species differ primarily in the degree to which the umbilicus is open, and some uncertainty attends the demarcation of a boundary between them. Xn any case, forms with the characteristics of M. caucasica (see Reiss, 1957) are very rare in these samples although they were reported by McGowran (1974) and Berggren et al. (197^0 to be relatively common in the eastern Indian Ocean. Stratigraphic Range; M. caucasica was observed only in the Morozovella formosa - M. aragonensis Zone at Site 220. Morozovella coronata Blow Globorotalia spinulosa Cushman, Bolli, 1957c, PI. 38, Figs. 6, 7. 1 1 Globoro talia (Globorotalia) spinulosa (Cushman)" of 211 Bolli, Blow, 1969, PI. 50, Figs. 2-5. Morozovella coronata Blow, Fleisher, 197^a, PI. 15* Figs. 1^ 2 (nomen nudumT. Globorotalia (Morozovella) spinulosa coronata Blow, in press(fide ¥. J. Clarke and P. Bronnimann, personal communication)• Remarks: At present the name Morozovella coronata is a nomen nudum, but clarification of the con cept is particularly important because this species, as used here, is of great biostratigraphic value. Bolli (1957c) illustrated two forms (PI. 38, Figs. 6, 7) which he thought to be representative of Globorotalia spinulosa Cushman. Xt has been widely agreed since that this species assignment was incorrect. Blow (1969) re ferred these specimens to 1 1 1 Globoro talia (Globorotalia) spinulosa (Cushman)1 of Bolli, 1957* (not Pulvinulina (sic) spinulosa Cushman, 1927 • . . ) * 1 1 and specifically cited to Bollifs Figures 6 and 7* He also illustrated his concept of the taxon (PI. 50, Figs. 2-5), and it was this form that he intended to rename as Globorotalia coronata in a paper that has not yet been published (W. A. Berggren, personal communication). Unfortunately, Blow’s illustrated specimens resemble Bolli*s (1957c, PI. 38) Figure 9* a specimen re ferred by Bolli to Globorotalia lehneri. more than they do his Figures 6 and 7. In not citing Bolli*s Figure 9* Blow apparently recognized that the specimen should not be 212 placed in Globorotalia lehneri. That conclusion is ac cepted here. The remaining question is important, how ever: is the form represented by Bolli1s Figures 6 and 7 conspecific with that of Figure 9* and if not, which con cept represents Blow's G. coronata? This question cannot be resolved here. The concept employed in this study of M. coronata is the same as that previously illustrated by Fleisher (l97^+a, PI. 15* Figs. 1, 2). These specimens are morphologically intermediate between Blow's specimens and Bolli*s Figures 6 and 7* Overall test form is similar to the latter; the forms have compact planoconvex tests with a weakly lobate periphery and with pronounced roughening of the umbilical shoulders. This morphology appears to be typical of the earlier forms of this species, i.e., specimens from the M. coronata — M. aragonensis Zone. Younger specimens resemble more closely the form illustrated by Blow. The umbilicus is relatively small, and the umbilical shoulders are less pronounced. The periphery is more distinctly lobate, and the keel, al though definitely present, is less pronounced. All speci mens, however, have non-limbate dorsal intercameral sutures, unlike the forms of Bolli*s Figures 6 and 7. Xt remains to be seen, therefore, whether the forms here referred to M. coronata are in accord with Blow's con cept. The preliminary evidence suggests that they are, but, if not, the name of the M. coronata - M. aragonensis 213 Zone should be modified. Stratigraphic Range: This species first appears at the base of the Morozovella coronata - M. aragonensis Zone, and ranges through the Truncorotaloides pseudo dub ius Zone at Sites 219 and 237* Morozovella lehneri (Cushman and Jarvis) Globorotalia lehneri Cushman and Jarvis, 1929> PI* 3* Fig. 16. Globorotalia lehneri Cushman and Jarvis, Bolli, 1957c, PI. 39. Fig. 11, not Figs. 9» 10, 12, 13. Globorotalia lehneri Cushman and Jarvis, Blow, 1969* PI* 50, Fig. 1. Morozovella lehneri (Cushman and Jarvis), Fleisher, 1974a, p. 1030. Remarks: The concept of this species used here is limited to forms with numerous narrow, elongate chambers in the final whorl, with an open umbilicus and roughened umbilical shoulders, and with a delicate and somewhat dis continuous keel. Stratigraphic Range: Very rare and poorly pre served specimens were observed in a few horizons from the Morozovella coronata - M. aragonensis and Globigerinatheka curryi - G. euganea Zones at all three sites. 214 Morozovella spinulosa (Cushman) Plate 6, Figures 7, 8 Globorotalia spinulosa Cushman, 1927, PI. 23, Fig. 4. Remarks: Cushman's illustration is a reasonably good representation of the holotype (examined by the author and by 0. L. Bandy), which is characterized by its bicon vexity and, most important, by the virtually closed umbilicus• Stratigraphic Range: Rare specimens of M. spinulosa were encountered at Site 237 in sediments from the Globigerinatheka senni and lower Morozovella coronata - aragonensis Zones. Morozovella sp. 1 ilate 7, Figures 6, 7 Remarks: The population designated Morozovella sp. 1 consists of small conicotruncate forms with a small, narrow umbilicus. The peripheral margin is keeled, but the keel is not always strongly expressed. The peripheral outline is rounded, and the four chambers per whorl are closely appressed. The dorsal intercameral sutures are distinct and marked by pseudospine development, as to a lesser extent are the umbilical shoulders. These sutures are slightly raised and arcuate; as a result, the chambers are lozenge-shaped to crescentic in dorsal view. 215 Stratigraphic Range: These forms are present only at Site 237, in the upper part of the Globigerinatheka curryi — G* euganea Zone* GENUS Neogloboquadrina Bandy, Frerichs, and Vincent, 19&7 Type Species; Globigerina dutertrei dfOrbigny Remarks: Neogloboquadrina was originally proposed for the single species Globigerina dutertrei dfOrbigny on purely phyletic grounds* This form is a virtually complete isomorph of Globoquadrina* possessing an umbilical aperture and, at least in one subspecies, strong umbilical teeth* Bandy et al, (1967) recognized, however, that G. dutertrei evolved from Globorotalia acostaensis Blow and Globorotalia humerosa Takayanagi and Saito, an evolutionary history com pletely independent of Globoquadrina* The lineage leading to Neogloboquadrina dutertrei can be traced with some con fidence to Globorotalia continuosa Blow (Bandy, 1972), which in turn appears to have arisen in the Early Miocene from Globorotalia siakensis LeRoy* Fleisher (197^-a) treated Neogloboquadrina as a mono- typic subgenus of Turborotalia and referred the remainder of the species in this bioseries, all of which lack typically developed umbilical teeth, to Turborotalia (Turborotalia)♦ A few other authors, however, notably 216 Collen and Vella (1973)* have applied Neogloboquadrina to related species other tlian N. dutertrei. Detailed studies by Toumarkine and Bolli (1970) of the lineage containing Turborotalia pomeroli have shown that this lineage evolved independently from the main sequence of Cenozoic turborotaliform species. Because the type species of Turborotalia is within this sublineage (i.e., T. cerroazulensis; see below), this generic name cannot be applied to the lineage leading to N. dutertrei for phyletic reasons. It appears, then, that Neo globoquadrina is the oldest available name for these species, and it has been so applied here. Because the ancestry of N. siakensis is not clear at this time, Neo globoquadrina is not applied to any species evolving prior to it. Neogloboquadrina continuosa (Blow) Globorotalia continuosa Blow, 1959* PI* 19* Pig* 125* Globorotalia (Turborotalia) continuosa Blow, Blow, 1969* PI. 3* Figs. 4-6 (holotype reillustrated). Turborotalia (Turborotalia) continuosa (Blow), Fleisher, 197^a, PI. 18, Fig. IO. Stratigraphic Range: N. continuosa was observed as occasional occurrences in the Globigerinatella insueta Zone at Site 219 only. 217 Neogloboquadrina mayeri (Cushman and Ellisor) Globorotalia mayeri Cushman and Ellisor, 1939> PI* 2, Fig. _ Globorotalia (Turborotalia) mayeri Cushman and Ellisor, Blow, 1969* PI* 3, Figs. 7-9 (holotype reillustrated). Turborotalia (Turborotalia) mayeri (Cushman and Ellisor), Fleisher, 197^a, PI. 19, Figs. 9, 10. Remarks: Blow (1969, p. 35l) suggested that N. mayeri may have evolved from G. ( F .) peripheroronda in temperate regions during the early Middle Miocene. At Site 237, however, well-developed populations of N. mayeri, with sharply recurved dorsal intercameral sutures and large comma-shaped apertures, are present throughout the Catapsydrax dissimilis Zone. This occurrence predates the commonly reported initial appearance horizons of both N. mayeri (Blow, 1969; Poag, 1972) and typical G. (F.) peri pheroronda. Morphologically, N. mayeri differs from N. siakensis only in the form of its dorsal sutures; it lacks, however, the slitlike aperture and distinctive secondary deposits over the early portion of the trochospire characteristic of G. ( F .) peripheroronda. These considera tions suggest the evolution of N. mayeri from N. siakensis and the assignment of the former to Neogloboquadrina. Stratigraphic Range: This species was noted only at Site 237, where it ranges through the Catapsydrax dis similis and basal Globigerinatella insueta Zones. It was 218 not observed in the G. insueta Zone at Site 219. Neogloboquadrina siakensis (LeRoy) Globorotalia siakensis LeRoy, 1939* PI. 3* Pigs. 30* 31- Globorotalia (Turborotalia) siakensis LeRoy, Blow, 1969, PI. 10, Figs” 7-9 (holotype reillustrated) j PI. 34, Figs. 4, 5. Turborotalia (Turborotalia) siakensis (LeRoy), Fleisher, 1974a, PI. 20, Figs. 9, 10. Stratigraphic Range: N. siakensis ranges From the top of the "Turborotalia” opima opima Zone at Sites 220 and 237 through the Globigerinatella insueta Zone at Site 219. GENUS Protentella Lipps, 1964 Type Species: Protentella prolixa Lipps. Remarks: Fleisher (1974a) discussed the status of Protentella with respect to Clavatorella Blow. Lipps (1966) was incorrect in concluding that Clavatorella is a junior synonym of this genus, but Blow (1965) was equally in error in suggesting that Protentella was a junior sub jective synonym of Bolliella and P. prolixa a junior synonym of B. adamsi. Both Protentella and Clavatorella are valid generic names and contain phyletically unrelated species which can be readily distinguished. 219 The most distinctive morphological basis upon which these forms can be separated is surface wall texture, Clavatorella evolved in the early Middle Miocene from Globorotaloides variabilis; the reticulate surface pattern is both distinctive and highly visible (Blow, 1965; Fleisher, 197^-a, PI. 5» Figs. 1, 2), The wall texture of Protentella was clearly illustrated by Fleisher (l97^+a, PI, 5, Fig, 6), and consists of densely distributed funnel-shaped pores scattered over a somewhat irregular surface. Pore pits and interpore ridges are not clearly developed, but neither are the flat interpore regions typical of Globigerina, This wall type appears to be developed as well in Protentella nicobarensis, a species originally placed in Clavatorella, Srinivasan and Kennett (197^-) noted that P. nicobarensis is similar in many respects, and probably related, to Beelladigitata. That conclusion is accepted here; moreover, the similarity of the walls of Beella digitata (see Jenkins and Orr, 1972, PI. 6, Figs. 7* 8) and P. nicobarensis, and the difference between this wall type and those of Clavatorella and Globigerina suggest that Protentella gave rise to Beellaby an increase in the height of the spire and a migration of the aperture to an umbilical position. The apertural lip on the two forms is strikingly similar and reflects this phyletic relationship. 220 Protentella cf, P. nicobarensis (Srinivasan and Kennett) Plate 8, Figures 1, 2 Clavatorella nicobarensis Srinivasan and Kennett, 197^, PI. 1, Figs # 1-13. Remarks: These authors placed their species in Clavatorella solely on the basis of gross test morphology (i.e., the radial elongation of* the chambers). The wall textures of P. nicobarensis and £. bermudezi are completely different, and there is no evidence of an evolutionary link between the two forms. The specimens observed here are generally similar in coiling pattern to P. nicobarensis (Srinivasan and Kennett), but most lack the distinctive chamber elongation of that species. The specimen represented in their Figure 8 most closely approximates the majority of the forms re covered at these sites. Stratigraphic Range: P. cf. P. nicobarensis was recovered at Sites 220 and 237» in sediments from the Globoquadrina binaiensis and "Turboro tali a1 1 kugleri Zones. One additional specimen was recovered at Site 237 from within the Catapsydrax dissimilis Zone. GENUS Pseudohastigerina Banner and Blow, 1959 Type Species; Nonion micrus Cole. 221 Remarks: Berggren et al, (1967) and Cordey et al, (1970) have discussed the evolution and phyletic trends within this genus, and no additional discussion is neces sary. Pseudohastigerina barbadoensis Blow Pseudohastigerina barbadoensis Blow, 19^9 > 53» Figs. 7-9; PI. 5^, Figs. 1-3. Pseudohastigerina naguewichiensis barbadoensis Blow, Fleisher, 197/ , la, p. 1031. Remarks: No specimens attributable to P. nague wichiensis were recognized in this study. In the absence of* comparative material, Blow's concept of* P. barbadoen sis . as differentiated from P. naguewichiensis. is tenta tively accepted. Stratigraphic Range: P. barbadoensis is present from the Turborotalia cerroazulensis Zone at Site 219 and the Globigerinatheka semiinvoluta Zone at Site 237 through the Cassigerinella chipolensis — P. barbadoensis Zone at the former, Pseudohastigerina micra (Cole) Nonion micrus Cole, 1927, PI. 3> Fig. 12. Hastigerina micra (Cole), Bolli, 1937c, PI. 33> Figs. 1, 2. Pseudohastigerina micra (Cole), Banner and Blow, 1939> Figs. 4g-i. 222 P seudohas tigerina micra (Cole), Berggren jet al. , 1967, Fig. 9. Remarks: P. micra is similar in form to P. barba- doensis, and tlie two have no doubt been confused (see Postuma, 197l)* P* micra is typically somewhat larger, as noted by Blow (1969* p. 410), but more diagnostic are the more compressed and closely appressed and less globular chambers• Stratigraphic Range: Specimens referred to P. micra first appear at the top of the Morozovella coronata M. aragonensis Zone at Site 219 and at the base of the Truncorotaloides pseudodubius Zone at Site 237* At the former locality it ranges part of the way up the Cassi— gerinella chipolensis — Pseudohastigerina barbadoensis Zone. Pseudohastigerina wilcoxensis (Cushman and Ponton) Nonion wilcoxensis Cushman and Ponton, 1932, PI. 8, Fig. 11. Globigerina pseudoiota Hornibrook, 1958, PI. 1, Figs. 16-18. Hastigerina eocenica Berggren, i960, PI. 10, Fig. 2. Pseudohastigerina wilcoxensis (Cushman and Ponton), Berggren et al., 1967, Text fig. 3* Nos. 2-5; Text fig. k, Nos. 2-5. Remarks: No specimens recognized as P. sharkriver— 223 ensis were encountered Stratigraphic Range: P . wilcoxensis ranges from the Morozovella formosa — M. aragonensis Zone at Site 220 through the lower part of the Truncorotaloides pseudo— dubius Zone at Site 237# GENUS Subbotina Brotzen and Pozaryska, 1961 Type Species: Globigerina triloculinoides Plummer. Remarks; The large and for the most part poorly known group of Paleogene globigeriniform species here placed in Subbotina have usually been referred to Globi— gerina. They are characterized, however, by a cancellate wall texture and an apertural lip or rim; furthermore, they are phyletically independent from the Globigerina lineage, except to the extent that G. officinalis ap parently evolved from a species of Subbotina in the Middle Eocene. On both morphologic and phylogenetic grounds, therefore, Subbotina and Globigerina are readily dis tinguished, despite a period of overlap in the Middle Eocene through Early Oligocene. The evolutionary patterns within Subbotina during the Paleocene and Early and Middle Eocene are not well established. McGowran’s (1968) proposed Subbotina bio series (lineage 4) excludes a number of species of major 224 importance (e.g., S. eocaena), and Stainforth’s (197^) treatment of these forms as a single evolving plexus derived from S» linaperta is felt here to be oversimplified. Furthermore, many species that apparently belong within this genus are used primarily in the Russian literature, but are poorly known elsewhere. Additional information about these forms will both clarify the taxonomic status of this group and increase its biostratigraphic useful ness. Several species morphologically indistinguishable from Subbotina s.s. have been placed in other genera for purely phyletic reasons. Toumarkine and Bolli (l970)> for instance, recognized an evolutionary bioseries leading from Globigerina frontosa Subbotina (including G. pata- gonica Todd) to Globigerina cerroazulensis Cole. The early species in this lineage are subbotinid in form, as is the late-stage offshoot Globigerina pseudoampliapertura Blow and Banner, but all species in the lineage are placed in Turborotalia. the type species of which is included. Similarly, Blow and Banner (1962) suggested the evolu tionary development of Globigerina ampliapertura and G. prasaensis (= G. euapertura) from Globigerina increbescens Bandy. These species are phyletically distinct, and thus excluded, from both Globigerina and Subbotina despite the similarities in morphology and wall texture with species of the latter. 225 Subbo tina angiporoid.es (Hornibrook) Globigerina angipora Stache, 1865, PI. 24, Pig. 36 (nomen dubium). Globigerina angiporoides Hornibrook, 1965* Figs, 1, 2, Globigerina (Subbotina) angiporoides angiporoides Horni brook, Jenkins, 1971, PI. 17, Figs. 510-513. Subbotina angiporoides (Hornibrook), Fleisher, 1974a, PI. 15, Fig. 7. Remarks: S. angiporoides has been used (see Blow, 1969) to designate a variety of forms in tbe Late Eocene and Early Oligocene which appear to have evolved from S. linaperta. These forms all have a compact test witb a narrow slitlike aperture, and tbe final chamber is common ly embracing and somewhat smaller than the penultimate. Following Jenkins (1966, 1971) and Jenkins and Orr (1973), this concept has been somewhat restricted here. S>. angiporoides is limited to specimens in which the final chamber is strongly embracing and in which a distinct lip is present. The concept employed here is that illustrated by Hornibrook (1965), Jenkins (l97l), and Blow (1969, PI. 12, Fig. 3, not Figs. 4, 5, 7). See S. minima and S. utilisindex. below, for a discussion of similar and closely related forms. Stratigraphic Range: S. angiporoides ranges from the Truncorotaloides pseudodubius Zone to the Turborotalia cerroazulensis Zone at Site 237* This species was not 226 distinguished in countings from £>. minima and S_. utilisin— dex at Site 219 (Fleisher, 1974a), but re-examination of the populations indicates that it ranges as high as the Cassigerinelia chipolensis — Pseudohastigerina barbadoensis Zone. Hare specimens were noted as well in the lowest sample recovered from the "Turborotalia" opima opima Zone at Site 220. This is somewhat higher than the level indicated by Blow (1969), and it is not clear whether it truly represents the upper limit of the species range. Subbotina corpulenta (Subbotina) Globigerina corpulenta Subbotina, 1953 (l97l)» Pi* 8, Figs. 5, 7; PI. 10, Figs. 1-4. Globigerina "corpulenta” Subbotina, Hagn and Lindenberg, I969, Fig. 6. Globigerina corpulenta Subbotina, Raju, 1971> PI. 5* Fig. 1. Subbotina corpulenta (Subbotina), Fleisher, 1974a, p. 1032. Remarks: Several authors (Hagn and Lindenberg, 1969; Lindenberg, 1969 ) have suggested that £>. corpulenta and S. gorcannii are merely population variants of S. eocaena, and that the names should be considered as junior subjective synonyms of that species. Stainforth (1974) has noted, on the other hand, that these forms— inter mediate in spire height between S. eocaena and S. gortanii— have been widely recognized and stratigraphically employed. Although the boundaries of the species as recognized in 227 this manner are somewhat indistinct, the recognizable specimens have been denoted here. Stratigraphic Range; Very rare specimens were noted in Sample 220-12-2, 70-72 cm, Morozovella coronata - M. aragonensis Zone. At Site 237* however, this species ranges from the top of the Globigerinathelca curryi — G . euganea Zone to the G. semiinvoluta Zone. These ranges are sufficiently discontinuous, and the specimens suf ficiently rare, to preclude an evaluation of the full range of this species in this basin. , II V Subbotina eocaena (Gumbel) Plate 8, Figure 3 Globigerina eocaena Gumbel, 1868, PI. 3* Fig. 109. Globigerina pseudoeocaena var. pseudoeocaena Subbotina, 1953 (1971), p i. Fig. 9; PI. 5, Figs. 1, 2, 6. Globigerina pseudoeocaena var. compacta Subbotina. 1953 (l97l), PI. 5, Figs. 3, 'i. Globigerina (Subbotina) eocaena Gumbel, Hagn and Linden berg, 1969* PI. 1, Figs.1-6 (neotype); Text fig. 6a. Subbotina eocaena (Gumbel) , Fleisher, 197^-a, PI. 15* Fig. 8. Remarks: As suggested by Hagn and Lindenberg (1969)* the concept of this species is taken to include G . pseudoeocaena s.l. Stratigraphic Range : S_. eocaena is present at all three sites and ranges from the Morozovella formosa — M. 228 aragonensis Zone at Site 220 to the Truncorotaloide s pseudodubius Zone at Site 219 and to the Turborotalia cerroazulensis Zone at Site 237# Subbotina eocaenica (Terquera) Globigerina eocaenica Terquem, 1882, PI. 9, Fig. 4. Globigerina eocaenica var. eocaenica Terquem, Subbotina, 1953 (1971), PI. 11, Figs. 8-11. Globigerina eocaenica var. irregularis Subbotina, 1953 (1971), PI. 11, Figs. 12-14. Subbotina eocaenica (Terquem), Fleisher, 1974a, PI. 15, Fig. 9- Remarks: The form illustrated by Subbotina (1971, PI. 11, Figs. 8, 9 in particular) typifies the concept of £>. eocaenica illustrated here. This species has a compact test with three to three and one—half chambers per whorl; the aperture consists of a slit or low arch. It is prob ably related to £>. linaperta, as suggested by Stainforth (197*0. Stratigraphic Range: At Site 219, S. eocaenica is restricted to the Middle Eocene Truncorotaloides pseudo- dub ius Zone, but at Sites 220 and 237 it ranges from the Globigerinatheka senni Zone to the G. semiinvoluta Zone. 229 Subbotina ^ortanii (Borsetti) Catapsydrax ^ortanii Borsetti, 1959* Pi* 1* Fig. 1. Globigerina turritilina turritilina Blow and Banner, 19&2 , PI. 13, Figs. D, E, F, G. Globigerina "gortanii" (Borsetti), Hagn and Lindenberg, 1969» Text fig. 6. Globigerina gortanii gortanii (Borsetti), Raju, 1971* PI* 2, Figs. 1, 2. Remarks: Hagn and Lindenberg (1969) suggested tbat _S. gortanii represents only a variant of S. eocaena. The morphology of this form, however, is distinctive and rela tively consistent. The abortive final chamber noted by Blow and Banner (1962) is present on most of the specimens observed in these samples. Stratigraphic Range: S. gortanii was noted as isolated specimens from the “Turborotalia" opima opima and Globoquadrina binaiensis Zones at Site 220 only. Subbotina hagni (Gohrbandt) Globigerina hagni Gohrbandt, 1967, PI* 1* Figs. 1-9* Remarks: A single specimen of S. hagni was found which appears to resemble the holotype very closely. Xt resembles some of the specimens illustrated by Subbotina (1971* PI* 5* Figs. 1, 2; not the holotype, PI. 4, Fig. 9) as G. pseudoeocaena. It is also similar to Globi— 230 ^erina ariakensis Asano (1962), which may prove to be a senior synonym. Stratigraphic Range: Tiie single specimen of S. hagni was found in Sample 237-27-^> 79-81 cm, within the Morozovella coronata - M. aragonensis Zone. This is with in the range reported by Gohrbandt (1967)* Subbotina inaequispira (Subbotina) Globigerina inaequispira Subbotina, 1953 (l97l)> PI* 6, Figs. 1-4. Stratigraphic Range: Isolated specimens were found at two horizons within the Globigerinatheka senni Zone at Site 237* Subbotina kiersteadae Fleisher Plate 8, Figures 6, 7» 8 Subbotina kiersteadae Fleisher, 197^a»Pl* l6, Figs. 1-9* Remarks: The characteristics used to define and recognize this species have been discussed in detail by Fleisher (l97^a)* Unlike most species assigned to this genus, S. kiersteadae has no apertural lip or rim. As discussed by Fleisher (l97^+a), however, this form seems to be the direct ancestor of Globigerinatheka senni, a con clusion supported by the thickened wall, distinct and en closed umbilicus, and frequently roughened umbilical 231 shoulders of S. kiers teadae, Subbotina linaperta (Finlay) Globigerina linaperta Finlay, 1939* PI. 23, Figs. 5^-57. Globigerina (Subbotina) linaperta Finlay, Jenkins, 1971, PI, 18, Figs. 551-551 *. Subbotina linaperta (Finlay), Fleisher, 197^a» p. 1033. Stratigraphic Range: £>. linaperta ranges from tbe Truncorotaloides pseudodubius Zone to the Turborotalia cerroazulensis Zone at Site 219# Subbotina minima (Jenkins) Plate 9* Figures 1, 2 Globigerina angiporoides minima Jenkins, 1966, Fig, 7* Nos. 52-57# Globigerina angiporoides Hornibrook, Blow, 1969* PI. 12, Figs. 4, 5. Globigerina (Subbotina) angiporoides minima Jenkins, Jenkins, 1971, PI. 17. Globigerina angiporoides Hornibrook, Raju, 1971, PI. 1, Fig. 8. Remarks: The recognized subdivision of S. angi- poroides has already been discussed. Jenkins (1966, 197l) distinguished this form from S. angiporoides solely on the basis of its smaller size, which appears from these samples to be a useful criterion. More diagnostic, how ever, is the lack of an embracing final chamber, a 232 feature taken here to be diagnostic of S. angiporoides. Stratigraphic Range: This species is restricted, at Site 2379 to the upper portion of the Globigerinatheka semiinvoluta Zone and to the Turborotalia cerroazulensis Zone. Although S. minima was not specifically distinguish ed at Site 2199 examination of picked specimens indicates that it ranges to the top of the recovered portion of the Cassigerinella chipolensis — Pseudohastigerina barbadoensis Zone. It is also present in the "Turborotalia" opima opima Zone at Site 220. Subbotina praeturritilina (Blow and Banner) Globigerina turritilina praeturritilina Blow and Banner, 1962, PI. 13, Figs, A, B, C. Globigerina gortanii praeturritilina Blow and Banner, Blow, 1969, PI. 17, Fig. 2. Globigerina gortanii praeturritilina Blow and Banner, Raju, 1971, PI. 2, Figs. 5, 5. Remarks; Blow and Banner (1962) discussed the basis upon which this species can be distinguished from S. gortanii. Stratigraphic Range: Isolated occurrences were ob served at Site 237 in the Truncorotaloides pseudodubius and Globigerinatheka semiinvoluta Zones. 233 Subbotina utilisindex (Jenkins and Orr) Plate 9* Figures 3* 4 Globigerina cf. angiporoides Hornibrook, Blow, 1969* PI* 12, Fig. 7* Globigerina sp. A, Beckmann, 1971* PI* 1* Figs. 1-4. Globigerina linaperta Finlay n. subsp., Jenkins and Orr, 1972, PI. 10, Figs. 6-8. Globigerina utilisindex Jenkins and Orr, 1973* PI* 1* Figs. 1-6; PI. 2, Figs. 1-9; PI. 3, Figs. 1-3* Remarks; Jenkins and Orr (1973) placed tbis species in Globigerina rather than Subbotina because it is unrelated to S. linaperta. has a "wall ornamentation . . . much less coarse than in the recorded species of Sub botina. t f (p. 134), and lacks an apertural lip. The first objection may be correct, but it does not directly affect the assignment to Subbotina in this case. The wall tex ture, i^hile less pronounced than in the illustrated speci mens of S. linaperta (PI. 3* Figs. 6, 7)* is nonetheless clearly cancellate. Finally, the absence of an apertural rim is not considered here to be a critical objection. This form is distinguished from S. angiporoides by the lack of an embracing final chamber and from both S. angiporoides and the more similar S. minima by the lack of an apertural lip. Stratigraphic Range: This species first appears in the Globigerinatheka semiinvoluta Zone at Site 237 (a single specimen in Sample 237—25—1, 79—81 cm, G. curryi — 234 G, eu^anea Zone, is probably contamination), and ranges as high, as the "Turborotalia” opima opima Zone (basal recover ed sample) at Site 220. / Subbotina winkleri (Bermudez) Globigerina winkleri Bermudez, 1961, PI. 6, Fig. 4. Globigerina aff. yeguaensis ¥einzierl and Applin, Blow and Banner, 1962, PI. 11, Figs. P, Q. Subbotina winkleri (Bermudez), Fleisher, 197^a, PI. 17* Fig. 1. Remarks: The specimen illustrated by Fleisher (l97^a) shows the small final chamber (i.e., bulla), a feature reported by Blow (1969) to have probably been pre sent on the holotype. Specimens from Site 237 show dis tinctly the umbilical teeth also described by Blow (1969); these specimens suggest that jS. winkleri may be related to Globoquadrina pseudovenezuelana or Catapsydrax riveroae. In either case, generic reassignment would be in order. Stratigraphic Range: S_. winkleri ranges from the basal Cassigerinella chipolensis — Pseudohastigerina barbadoensis Zone at Site 219 through the basal sample of the “Turborotalia” kugleri Zone at Site 237* Subbotina sp. 1 Plate 8, Figures 4, 5 Remarks: The specimens included in this taxon con- 235 sist of chambers arranged in a low trochospire and flat tened test form, with, four to four and one—half chambers in the final whorl* The umbilicus is relatively broad and open, but is commonly covered with a small bulla or abortive chamber which appears to be imperforate or very finely perforate. Under the bulla, visible when it is broken, are distinctive flaps which extend from the umbilical margin of each chamber into the umbilicus; these also appear to be imperforate. The chambers are globular and loosely appressed, and the sutures are distinct and deeply incised. The aperture consists of a low arch open ing into the umbilicus. The affinities of this form are unclear, but its appearance suggests a relationship of some sort with S. eocaena. Stratigraphic Range: Subbotina sp. 1 was observed only at Site 237> where it is present in the Globigerina theka semiinvoluta and Turborotalia cerroazulensis Zones. GENUS Tenuitella Fleisher, 197^ Type Species: Globorotalia gemma Jenkins. Remarks: Included in Tenuitella is a group of closely related species characterized by a microperforate test wall and, typically, by their markedly small size. Fleisher (197^3-) discussed the phylogeny of these 236 species, of which little is presently known. In practice, they have received little attention because of their small size, and cannot be arranged into a phylogenetic pattern whose transitions have been documented. Nevertheless, Fleisher listed twelve species whose morphological features (most notably wall texture) suggest that they should be placed in Tenuitella. Several additional forms have subsequently been noted, of which the most important are Tenuitella permicra (= Globorotalia (Turborotalia) permicra Blow and Banner), T. angustiumbilicata (Bolli), and T . iota (= Globigerinita iota Parker). The morphological characters which seem to dis tinguish this group include wall type, chamber arrange ment, apertural position and modifications, and the ap parently consistent lack of a keel. All known species consist of chambers arranged in a low trochospire, typi cally with a flat spiral side. On one hand, however, specimens of some forms (notably T . gemma) may become planispiral in the later ontogenetic stages; on the other, T. angustiumbilicata has developed a flattened globigerinid form. Nevertheless, the generalized morphological characterization holds for most species, as does the typical extraumbilical position of the aperture. This position may vary to the point of being symmetrically peripheral in planispiral specimens of T. gemma or pri marily umbilical in T. angustiumbilicata. All known 237 species have at least a small apertural lip, which may in some forms be extended into a large and distinct flap (Tenuitella sp. l) or be represented (replaced?) by a bulla (T. praestainforthi. T. iota). Finally, the only carinate form known to have a microperforate wall, Globorotalia in— conspicua Howe, has been placed in Testacarinata (Jenkins, 197l) and probably represents a distinctive but short lived offshoot of Tenuitella. The microperforate wall texture of these forms dis tinguishes them from all other post-Paleocene genera. Thus such forms as the microperforate "Globorotalia continuosa” of Krasheninnikov and Hoskins (1973, PI. 19, Figs. 10—12) belong in Tenuitella, and the specimen identified as “Globorotalia anfracta” by Jenkins and Orr (1972, PI. 20, Figs. 4-6), which possesses a cancellate wall, is not con- specific with T. anfracta and probably should be placed in Globorotaloides. Differentiation of Tenuitella and Globigerinita is based upon both morphologic and phylogenetic grounds. The initial appearance of the Globigerinita lineage is marked by the evolution of G. boweni from T. clemenciae in the Late Oligocene. All of the species known to evolve from G. boweni differ in chamber arrangement from those here placed in Tenuitella. These forms may be said to be globigeriniform; that is, species of Globigerinita have tests whose chambers are subglobular, loosely appressed, 238 and arranged in a low but not flat trochospire (e.g., G. glutinata)• Tbe chambers of most species of Tenuitella are less spherical and are arranged in a very flat trocho— spiral series. In most of the former, the aperture is umbilical; this is true among Tenuitella species only for T. angustiumbilicata. The evolution of T. angustiumbili cata much predates the appearance of G. boweni, however, and it should accordingly be placed in Tenuitella. Tenuitella angustiumbilicata (Bolli) Plate 10, Figures 1, 2, 3 Globigerina ciperoensis angustiumbilicata Bolli, 1957b, PI. 22, Figs. 12, 13. Globigerina angustiumbilicata Bolli, Jenkins and Orr, 1972, PI. k, Figs. 5, 6; PI. 5, Figs. 6-8. Globigerina angustiumbilicata Bolli, Krasheninnikov and Hoskins, 1973, PI. 5, Figs. 8-10 (?). Remarks; Most of the scanning electron micrographs illustrating “Globigerina1 1 angustiumbilicata have portrayed specimens with the gross test morphology of Bolli*s holo type and with a microperforate wall texture. One exception at least, the form illustrated by Poag (1972; PI. 11, Figs. 3, 4), is almost certainly rnisidentified, in that it has an open umbilicus and lacks an apertural lip. From ¥. C. Meyer the author has obtained topotype specimens from Bolli*s (l957b) Sample Bo 291A locality; these specimens, identical in gross test morphology to Bolli*s holotype of 239 G. angustiumbilicata, have a microperforate wall* In view of* the origin of these forms in the Late Eocene (Blow, 1969) or Early Oligocene (Fleisher, 1974a), it is evident that this species should be placed in Tenuitella. Stratigraphic Range: T . angustiumbilicata first appears in the Cassigerinella chipolensis - Pseudo- hasti gerina barbadoensis Zone at Site 219* It is present sporadically in the Globoquadrina binaiensis Zone at Site 220, and consistently in and above the "Turborotalia” opima opima Zone at Site 237* Tenuitella clemenciae (Bermudez) Plate 10, Figure 4 ✓ Turborotalia clemenciae Bermudez, 1961, PI* 17, Fig. 10* Globorotalia (Turborotalia) munda Jenkins, 1966, Fig, l4, Nos. 126-133; Fig. 15, Nos. 152-166. / Globorotalia (Turborotalia) clemenciae (Bermudez), Blow, 1969, PI. 35, Fig* 8. Globorotalia continuosa (Bermudez), Krasheninnikov and Hoskins, 1973, PI. 19, Figs. 10-12. Tenuitella clemenciae (Bermudez), Fleisher, 1974a, PI. 17, Fig. 8. Remarks: There seems to be no way in which T. clemenciae and T. munda can be consistently differentiated. Fleisher (1974a) suggested that specimens of the former have more inflated and subglobular chambers, but this feature varies widely within what are clearly single 240 populations* Jenkins * s sp< • les has therefore been placed n synonymy* Strat 1graph!c Ranye; This species is present as , ov ! as the basal sediments recovered from the "Turboro- a l i a opima opima Zone at Sites 220 and 237> and ranges s high as the top of the Globigerlnatella insuet a Zone, to he extent that it is complete, el Site 219* Tenuitella gemma (Jenkins) Plate 9 9 Figure 5 Globorotalia gemma Jenkins, 1966, Fig. 11, Nos. 97—103* Globorotalia (Turborotalia) gemma Jenkins, Blow, 1969* PI* 3b, Fig. 9. Globoro talia gemma Jenkins, Jenkins and Orr, 1972, PI. 22, Figs. 7-11* Tenuitella gemma (Jenkins), Fleisher, 19T^a» PI* 17# Figs. g 6, 7. Remarks: T. gemma can be differentiated from T. nr!nut i s inna , whi ch it resembles, by its somewhat more globular and discrete chambers and. by its more open and less peripheral aperture. Strati gr a ph. 1 c Range : For the most part, T. gemma has not been reported higher than the top of the Cassi— gennella chipolensis — Pseudohastigerina barbadoensis Zone ( 1 , o , top of P, 19)* X 1 Is found within that zone (and no lower) at Site 219, but ranges through the "Tur- 241 borotalia” opima opima Zone at Site 220 and through the Globoquadrina binaiensis Zone at Site 237. Tenuitella minutissima (Bolli) Globoro talia minut i s s ima Bolli, 1957t>> PI* Pig* 1* Remarks: See comments, above, for T. gemma. The specimens assigned by Lipps (1 9 6 k) to Boglobigerina minutissima (PI* 4, Figs. 4-6) are less compact than Bolli*s forms and probably belong elsewhere, perhaps in T. angus t iumb ilicata. Stratigraphic Range: This form was recognized only at Site 237f where it was consistently present, and usual ly common from the "Turborotalia” opima opima Zone to the Globigerinatella insueta Zone. Tenuitella cf. T. nlcbrowni (Bronnimann and Resig) Plate 11, Figures 1, 2 Globorotalia (Turborotalia) nkbrowni Bronnimann and Resig, 1971, PI. ^0, Figs. 1-8. Remarks: Forms assigned to Tenuitella cf. T. nkbrowni are common in a number of samples in the Early Miocene at Site 237* These minute forms bear a general resemblance to T. nkbrowni in their general morphology; they consist of about five chambers per whorl arranged in a flattened trochospire. These forms are most similar, it 242 appears, to the specimen illustrated by Bronnimann and Resig (l97l) in their PI. 40, Pig. 7* The resemblance, however, is not exact. The chambers seem to be somewhat more inflated than are those of T. nkbrowni, the spire is somewhat higher, and the dorsal accessory apertures of T. nkbrowni were not ob served, at least in reflected light. Stratigraphic Range: T. cf. T. nkbrowni is present and often common in the fine fraction of samples from the middle of the "Turborotalia1 1 kugleri Zone to the upper part of the Catapsydrax dissimilis Zone at Site 237* Tenuitella praestainforthi (Blow) Plate 10, Figures 5* 6 Globigerinita stainforthi praestainforthi Blow, 1969* PI* 25, Figs. 3-5. Remarks: Blow (1969) noted the differences in wall texture between his new taxon and Catapsydrax stainforthi Bolli, Loeblich, and Tappan. On the basis of overall test form he related these two at the subspecies level. In fact, the latter has a cancellate wall typical of Cata psydrax t while the wall texture of Blow's form is micro- perforate* For this reason this form is placed in Tenui tella; the similarity in test form is a striking example of nearly contemporaneous isomorphism in essentially un related forms. 243 Strati graphic Range: T. praestainforthi occurs in the "Turborotalia” opima opima Zone at Site 220, and in the uppermost Globoquadrina binaiensis Zone and “Turboro talia” kugleri Zone at Site 237* Tenuitella sp. 1 Globorotalia sp. 4, Jenkins and Orr, 1972, PI. 18, Figs 7-12. Tenuitella sp. 1, Fleisher, 197^a, PI. 17* Fig. 5# Remarks: This form, which is consistently rare, is characterized by a pronounced apertural-umbilical flap. Stratigraphic Range: Tenuitella sp. 1 is present as a single specimen in Sample 237-21-1, 79-81 cm, near the base of the “Turborotalia” kugleri Zone. GENUS Truncorotaloides Bronnimann / and Bermudez, 1953 Type Species: Truncorotaloides rohri Bronnimann / , and Bermudez (= junior synonym of Globigerinoides pseudo- dubia Bandy). Remarks: In the concept employed here, the name Truncorotaloides is used for only a few noncarinate species with pseudospinose walls in which secondary dorsal sutural apertures are a persistent structural element. Keeled 2 kk forms with accessory apertures of this kind, such as Morozovella bandyi, are excluded. McGowran (1968), partially on phyletic grounds, proposed that Acarinina and Truncorotaloides be dis tinguished only at the subgeneric level. This suggestion has much to recommend it; recent studies have clearly indicated the presence of secondary apertures, at least occasionally, in a variety of Paleogene globorotaliform species (Premoli Silva and Bolli, 1973* PI# 9* 10). Nevertheless, any reorganization of these genera should be based at least in part on established phyletic histories for these species. The present state of knowledge of Paleogene lineages among these forms is not sufficient to warrant this reclassification until more data are avail able. Truncorotaloides collacteus (Finlay) Globorotalia collactea Finlay, 1939* PI# 29* Figs. 164, 165. Truncorotaloides collactea (Finlay), Jenkins, 1965c, Figs. 1-27. Truncorotaloides collacteus (Finlay), Fleisher, 197^a, PI. 18, Figs. 3^ £. Remarks: This species is similar to T. pseudo dub ius but is smaller and consistently shows a much small er umbilicus. The secondary apertures are not visible on all specimens. Stratigraphic Range; T. collacteus ranges from within the Globigerinatheka senni Zone at Sites 220 and 237 to the top of the Truncorotaloides pseudodubius Zone (Site 219) or slightly higher (Site 237)* Rare specimens in the Turborotalia cerroazulensis Zone at Site 219 were noted as T. aff. T. collacteus. Truncorotaloides pseudodubius (Bandy) Globigerinoides pseudodubia Bandy, 1949, PI# 24, Fig* 1. Truncorotaloides rohri Bronnimann and Bermudez, 1953, PI# 87, Figs. 1-12. Truncorotaloides pseudodubius (Bandy), Fleisher, 197^a, PI. 18, Figs. 1, 2. Stratigraphic Range: This species ranges from with in the Globigerinatheka senni Zone at Site 220, and from the base of the Morozovella coronata — M. aragonensis Zone at Site 2379 to the top of the Truncorotaloides pseudo dubius Zone. Truncorotaloides cf. T. topilensis (Cushman) Plate 11, Figure 3 Globigerina topilensis Cushman, 1925a* PI# 1* Fig. 9# Truncorotaloides topilensis (Cushman), Bolli, 1957c, PI. 39, Figs. 13-16. Truncorotaloides aff. topilensis (Cushman), McGowran and Lindsay, 1969, PI. 1, Figs. 15, 19-30. Truncorotaloides topilensis (Cushman), Samanta, 1973, PI# 6, Figs. 9, 10. 246 Remarks: Typical specimens of T, topilensis con sist of loosely appressed and highly angular chambers. The specimens observed here, however, more closely resemble those illustrated by McGowran and Lindsay (1969) and Saraanta (l973)« The coiling in these forms, and the angularity of the chambers, is intermediate between that of Bolli!s (l957c) specimens and that exhibited by T* pseudodubius, Stratigraphic Range; Rare specimens of T, cf, T, topilensis were observed from the lower portion of the Morozovella coronata - M. aragonensis Zone to the basal T, pseudodubius Zone at Site 237* * GENUS Turborotalia Cushman and Bermudez, 1949 Type Species: Globorotalia centralis Cushman and Bermudez, Remarks: Turborotalia, originally described by Cushman and Bermudez (1949) as a subgenus of Globoro talia, was initially differentiated on the basis of the presence of a rounded peripheral margin. This definition was sub sequently modified by Loeblich and Tappan (1964) and Blow (1969)* who restricted Turborotalia (at the generic and subgeneric level respectively) to globorotaliform species lacking an imperforate peripheral keel or band. Most 247 authors who have recognized Turborotalia as a valid and useful taxon have accepted this redefinition. Fleisher (l974a) demonstrated that the distinction between keeled and nonkeeled forms at the generic or sub- generic level is without phyletic significance, in that the generic boundary drawn in this manner cuts across several independent recognized lineages. In at least eleven separate instances, carinate descendents arose from noncarinate ancestors. Globorotalia, therefore, is strikingly polyphyletic as so distinguished. As an alternative, Globorotalia was restricted (Fleisher, 1974a) to include only those Neogene species with a finely perforate wall. Turborotalia was also recog nized very largely on the basis of surface texture and, as a means of distinguishing it from Subbotina. apertural position. In this manner, it was interpreted as including species with a cancellate nonspinose wall and an extra- umbilical or umbilical—extra—umbilical aperture bordered by a distinct imperforate rim or lip. The few exceptions to these generalizations (e.g., T. pseudoampliapertura, T. ampliapertura) were recognized as direct descendents of turborotaloid ancestors. Reservations were expressed (p. 1034) at that time about the monophyly of Turborotalia as so defined. Tou- markine and Bolli (1970) postulated a bioseries arising from the globigeriniform species T. frontosa (including T. 248 patagonica and T. boveri of this report) and culminating in T. cerroazulensis cunialensis. Their proposed lineage contains the type species of Turborotalia and, if valid, would require the restriction of the application of this generic name to elements of this series. Fleisher ( 1 9 7 regarded T. cerroazulensis pos- sagnoensis as the critical form in evaluating this line age, as it appeared to represent the transition from a globigeriniform to a turborotaliform test. Dr. H. M. Bolli has kindly provided specimens of this subspecies for examination. T. cerroazulensis possagnoensis has an elongate slitlike aperture, lower than and different from the apertural form typical of either T. frontosa or T. pomeroli. The apertures of the latter two species form distinct and relatively high arches, and primitive forms of T. pomeroli. reminiscent in form of "Turborotalia” ampliapertura (Bolli), appear to represent a morphotype transitional between them. Although T. cerroazulensis possagnoensis appears to represent a short-lived offshoot of T. frontosa. the phylogenetic reconstruction suggested by Toumarkine and Bolli (1970) appears to be otherwise correct. The name Turborotalia. therefore, should be re stricted to the taxa directly related to this lineage, which appears to be phyletically independent from all other Paleogene and Neogene turborotaliform species with 2^9 cancellate walls. Some of the latter* have been placed in Neogloboquadrina. and the remainder in ” Turborot alia1 1 (see below). Turborotalia boweri (Bolli) Globigerina boweri Bolli, 1957c, PI# 36, Fig# 1, not Fig. 2# Subbotina boweri (Bolli), Fleisher, 197^a, p. 1032. Remarks: Three closely related late Early and early Middle Eocene forms, Globigerina boweri Bolli, G. patagonica Todd and. Kniker, and G. frontosa Subbotina, have been very widely confused. Most frequently the morphotypes represented by all three holotypes have been considered synonymous, and the group usually has been referred to either G. boweri or G. frontosa. ¥ith a few exceptions (e.g., Bandy and Kolpack, 1963)* Todd* s species name has not been employed. The author has compared holotypes of G. boweri and G. patagonica. and has concluded that they are significant ly different. The type illustration of G. boweri is decep tive in that it does not portray with sufficient clarity the strongly flattened dorsal surface and the subacute peripheral margin, particularly along the early chambers of the final whorl. The dorsal chamber surfaces of G. patagonica. by contrast, are clearly rounded, as is the 250 periphery, and the dorsal surface as a whole is somewhat convex. All three forms, in this report, are placed in Turborotalia for phyletic reasons. T. boweri appears to represent a distinct derivative of T. patagonica but it does not appear to have any direct descendents. Neither T. possagnoensis nor T. pomeroli shows the characteristic flattened dorsal surface of T. boweri. Stratigraphic Range: T. boweri was observed in the lowermost Globigerinatheka senni Zone at Site 220 and ranges as high as the Morozovella coronata — M. aragonensis Zone. Isolated occurrences within the zone were also noted at Sites 219 and 237# Turborotalia cerroazulensis cerroazulensis (Cole) Globigerina cerroazulensis Cole, 1928, PI. 32, Figs. 11—13# ✓ Globorotalia centralis Cushman and Bermudez, 1937» PI* 2, Figs • 62-64*j not 6>5. Globorotalia cerroazulensis cerroazulensis (Cole), Tou- markine and Bolli, 1970> PI# 1* Figs. 19-24. Turborotalia (Turborotalia) cerroazulensis cerroazulensis (Cole), Fleisher, 1974a, PI. 19, Fig. 1. Remarks; Toumarkine and Bolli (1970) reported that the holotype of Globorotalia centralis (Fig. 65 of Cushman and Bermudez, 1937) is lost. As they noted, all of the paratypes are clearly conspecific with Globigerina cerro- 231 azulensis Cole and, no matter which is eventually chosen as a neotype, Cole’s species must be considered a senior synonym of Globorotalia centralis. Globigerina cerro azulensis thus becomes the type species of Turborotalia, Stratigraphic Range: This species is first ob served in the Truncorotaloides p s eudo dub ius Zone at Site 219; a single occurrence, in Sample 237-25-1, 79-81 cm (uppermost Globigerinatheka curryi - G. euganea Zone) is probably reworked. T. cerroazulensis s.s. ranges to the upper Globigerinatheka semiinvoluta Zone at Site 219, and to the top of the T. cerroazulensis Zone at Site 237* Turborotalia cerroazulensis cocoaensis (Cushman) Globorotalia cocoaensis Cushman, 1928, PI. 10, Fig. 3* Globorotalia (Turborotalia) cerroazulensis (Cole), Blow, 1969, PI. 36, Figs. 3, 4. Globorotalia cerroazulensis cocoaensis Cushman, Toumarkine and Bolli, 1970, PI. 1, Figs. 28-33. Turborotalia (Turborotalia) cerroazulensis cocoaensis (Cushman), Fleisher, 197^a, p. 1035. Remarks: This subspecies includes forms with angular to subangular but noncarinate peripheral margins. Specimens with subangular margins along only part of the periphery (e.g., Toumarkine and Bolli, PI. 1, Figs. 25-27) are placed in T. cerroazulensis s.s. 252 Stratigraphic Range: Isolated occurrences of rare specimens were noted in the Truncorotaloides pseudodubius through Turborotalia cerroazulensis Zones at Site 219, and within the latter at Site 237. Occurrences of this and other subspecies of T. cerroazulensis in Sample 219-16-4, 52-54 cm, are probably reworked. Turborotalia cerroazulensis cunialensis (Tourmarkine and Bolli) Globorotalia cerroazulensis cunialensis Toumarkine and Bolli, 1970, PI. 1, Fig. 37-39. Turborotalia (Turborotalia) cerroazulensis cunialensis (Toumarkine and Bolli), Fleisher, 1974a, p. 1035. Remarks: This subspecies is characterized by its carinate margin and is the only form included within Turborotalia to develop a keel. Stratigraphic Range; A single rare occurrence of T . cerroazulensis cunialensis was noted in the T. cerro azulensis Zone at Site 237. It is also present, but probably reworked, in Sample 219-16-4, 52-54 cm. Turborotalia cf. T. frontosa (Subbotina) Globigerina frontosa Subbotina, 1953 (l97l), PI. 12, Figs. 6, 7; not Figs. 3 (holotype), 4, 5. Globigerina boweri Bolli, 1957c, PI. 36, Fig. 2, not Fig. 1. 253 Globigerina frontosa Bolli, Saraanta, 1973* PI# 1* Figs. 22-24. Remarks: Three separate forms appear to be present in Subbotina*s type series. The holotype (Subbotina, 1953 (l97l) 9 PI# 12, Fig. 3) is identical with the holotype of Globigerina patagonica Todd and Kniker, and G. frontosa is placed in synonymy with this taxon. The apertures of two of these specimens (Figs. 4, 5) consist of a very low arch or slit, and these forms belong in Turborotalia possagnoen sis. The remaining two specimens, for which no valid or available name appears to be at hand, are placed here in T. cf. T. frontosa and differ in form from T. boweri in having a rounded periphery and from both T. boweri and T. patagonica in having a compact and distinctly quadrate test. They also differ from T. patagonica in the lack of inflatation of the dorsal chamber surfaces. Bolli*s (l957c, PI. 36, Fig. 2) specimen was not examined, but it appears to have an arched rather than slitlike aperture (see also the description, Bolli, 1957c, p. 163) and this belongs in T. cf. T. frontosa rather than T. possagnoensis. Stratigraphic Range: This species is present only at Site 237* where it occurs in most samples in the Globigerinatheka senni Zone, and in a few samples in the lower Morozovella coronata - M. aragonensis Zone. 254 Turborotalia patagonica (Todd and Kniker) Globigerina patagonica Todd and Kniker, 1952, PI. 4, Fig. 32. Globigerina frontosa Subbotina, 1953 (l97l)» PI* 12, Fig. 3 (holotype). / Globigerina ayalai Bermudez, I96I, PI* 1» Fig* ^* Globigerina frontosa Subbotina, Toumarkine and Bolli, 1970, PI. 1, Figs. 1-3* Globigerina frontosa Subbotina, Postuma, 1971* P* 1^5* Subbotina patagonica (Todd and Kniker), Fleisher, 197^a, PI. 17, Figs. 2, 3. Remarks: The basis for distinguishing T. pata gonica from T, cf. T. frontosa and T. boweri has already been discussed. Globigerina ayalai is virtually identical with T, patagonica. differing only in having slightly more globular chambers. It is considered to fit within typical populations of this species, Stratigraphic Range: T. patagonica first appears in the Morozovella formosa — M. aragonensis Zone at Site 220, and ranges as high as the M. coronata - M. aragonensis Zone at all three sites. Turborotalia pomeroli (Toumarkine and Bolli) Globorotalia cerroazulensis pomeroli Toumarkine and Bolli, 1970, PI. 1, Figs. 10-18. Turborotalia (Turborotalia) cerroazulensis pomeroli (Tou markine and Bolli), Fleisher, 197^-a, PI. 199 Figs. 2, 3* 255 Remarks: See comments above for T, cerroazulensis s. s. T. pomeroli was erected for tlie morpliotype formerly associated with. T* centralis, Stratigraphic Range; T. pomeroli first appears in the upper Globigerinatheka senni Zone at Site 220 and in the Morozovella coronata - M. aragonensis Zone at Sites 219 and 237* The early forms at Sites 220 and 237 are similar in form to "Turborotalia” ampliapertura, in having a primarily umbilical but slightly extra—umbilical aper ture and four chambers in the final whorl. They seem to be transitional between T, patagonica and typical T. pomeroli. This species ranges to the top of Turborotalia cerroazulensis Zone at Sites 219 and 237* Turborotalia cf, T. possagnoensis (Toumarkine and Bolli) Globigerina frontosa Subbotina, 1953 (l97l)> PI* 12, Figs, k, 5; not Fig, 3 [holotype). Globorotalia cerroazulensis possagnoensis Toumarkine and Bolli, PI, 1, Figs, 4-9* Remarks; Fully typical specimens with slitlike apertures were not observed. The forms recorded here have apertures consisting of arches lower than those typical for other forms in this bioseries, Stratigraphic Range: Isolated specimens were found 256 only at Site 237» in the lower Morozovella coronata - M. aragonensis Zone# Turborotalia pseudoampliapertura (Blow and Banner) Globigerina pseudoampliapertura Blow and Banner, 1962, PI# 17, Figs. A, E# Globigerina ampliapertura pseudoampliapertura Blow and Banner, Srinivasan, 1968, PI. 17, Figs. 4-6. Globigerina pseudoampliapertura Blow and Banner, Blow, 1969, PI. 18, Figs. 8, 9. Turborotalia (Turborotalia) pseudoampliapertura (Blow and Banner), Fleisher, 1974a, PI. 20, Fig. 8. Remarks: Although this species is characterized by an umbilical aperture and is thus commonly placed in Globigerina. Blow and Banner (1962) documented its evolu tion from T. centralis (= T. pomeroli). From a phyletic standpoint, therefore, T. pseudoampliapertura cannot be placed in either Subbotina or Globigerina. Stratigraphic Range: Turborotalia pseudoampli apertura is limited to the T. cerroazulensis Zone at Site 237 and to the Casslgerinella chipolensis - Pseudo- hastigerina barbadoensis Zone at Site 219. GENUS “Turborotalia,1 1 non Turborotalia / Cushman and Bermudez Remarks: If Turborotalia, as that taxon is treated 237 here, is reserved for the species of4 the T. patagonica - T. cerroazulensis lineage, there appears to be no suitable genus-level taxon to accommodate the remaining species with cancellate nonspinose surface textures and extra- umbilical lipped apertures* Some of these have been placed in Neogloboquadrina, a genus which includes the forms that fall within the lineage leading to N. dutertrei* The few attempts to construct lineages for the remainder of the Cenozoic species showing these morphologic features (McGowran, 1968; Berggren, 1968), however, have not proved very useful, largely because they include few of the species that have been recognized. The erection of a new generic name is not warranted until the phyletic history of these species has been more firmly established. For the present, accordingly, they are here placed in "Turborotalia, 1 1 Included as well are a few species with umbilical apertures which have been shown to evolve from more typical turborotaliid species, "Turborotalia" ampliapertura (Bolli) Globigerina ampliapertura Bolli, 1957^, PI, 22, Figs. 5-7. Globigerina amp1iapertura Bolli, Blow, 1969, PI# 12, Figs, 6, 9, 10. Turborotalia (Turborotalia) ampliapertura (Bolli), Fleisher, 197^a, PI. 18, Fig. 6. 258 Remarks: Blow and Banner (1962) showed that this form evolved from "Turborotalia” increbescens. and it therefore belongs in this genus rather than in Subbotina, As suggested earlier, it appears probable from comparative morphology that "T." ampliapertura is the ancestor of the lineage recognized here as "Globigerina," When more is known of this evolutionary sequence, it may prove desirable to consider "T," ampliapertura as the earliest species in cluded in "Globigerina," Stratigraphic Range: "Turborotalia" ampliapertura ranges from the Turborotalia cerroazulensis Zone to the Cassigerinella chipolensis - Pseudohastigerina barbadoensis Zone at Site 219* A single occurrence was noted in Sample 237—22—2, 79-81 cm, within the Globoquadrina binaiensis Zone , "Turborotalia" bella (Jenkins) Plate 11, Figures U9 5 Globorotalia siakensis LeRoy, Jenkins, i960, PI, 5» Fig. 7« Globorotalia bella Jenkins, 1967* Fig. 3> Nos. 1—6. Remarks: The specimens observed here correspond well to Jenkins's (1967) holotype. Wall texture, although cancellate nonspinose, appears finer and smoother than is typical for most species of this group. The suggested relationship (Jenkins, 1967> 197l) 259 between "T, 1 1 bella and Globoro talia (Fohsella) periphero- ronda has been discussed above (see “Remarks” for G. (F.) aff. G. (F.) peripheroronda). Stratigraphic Range: Tbis species was found only in the Globigerinatella insueta and upper Catapsydrax dis- similis Zones at Site 237* “Turborotalia” aff* "T." bella (Jenkins) Plate 11, Figure's 6 , ^ Remarks: This form is quite similar to "T." bella except that virtually all specimens have only four, as op posed to four and one-half, chambers per whorl. They ap pear to represent intermediate stages in the evolutionary sequence from “Turborotalia” opima nana to "T." bella* This transition involves a decrease in wall thickness and in the prominence of the apertural lip, and an increase in inflation and distinctness of the chambers. Stratigraphic Range; This form ranges from the upper part of the ”T.M kugleri Zone to the Globigerinatella insueta Zone at Site 237* ! I T. “ opima nana and "T." aff. "!£• " do not overlap, but the highest occurrence of the former and the lowest of the latter are very close within the upper portion of Core 20. 260 "Turborotalia" birnageae (Blow) Globorotalia birnageae Blow, 1959? PI# 17* Fig# 108. Globorotalia (Turborotalia) birnageae Blow, Blow, 19&9* PI. 3b, Figs. 7, 8. Turborotalia (Turborotalia) birnageae (Blow), Fleisher, 1974a, PI. 18, Fig. 9# Remarks: Although Blow (1959) described his species as "finely perforate," the holotype, like the specimens illustrated by Blow (1969) and Fleisher (1974a), is strongly cancellate and nonspinose. Stratigraphic Range: "T. " bimageae is present in the Catapsydrax dissimilis Zone at Site 237 and in the Globigerinatella insueta Zone at Sites 219 and 237# "Turborotalia" bolivariana (Petters) Globigerina wilsoni var. bolivariana Petters, 1954, PI# 8, Fig. 9# Globorotalia bo1ivariana (Petters), Bolli, 1957c, PI. 37* Figs . l4—"16 • Turborotalia (Turborotalia) bolivariana (Petters, Fleisher, 1974a, p. 1035# Stratigraphic Range: A single specimen was found in Sample 220—12—CC (Morozovella coronata — M. aragonensis Zone). 261 "Turborotalia" euapertura (Jenkins) Globigerina euapertura Jenkins, i960, PI* 1, Pig* 8. Globigerina ampliapertura euapertura Jenkins, Blow and Banner, 1962, PI. 11, Figs. ID, F, G. Globigerina prasaepis Blow, 1969, PI* 10, Fig. 13; PI* 18, Figs. 3-7. Globigerina euapertura Jenkins, Berggren and Amdurer, 1973, PI. 23, Figs. 7,8. Turborotalia (Turborotalia) euapertura (Jenkins), Fleisher, 1974a, p. 1035. Turborotalia (Turborotalia) prasaepis (Blow), Fleisher, 197^a, PI. 20, Fig. 7. Remarks: Berggren and Amdurer (1973) reported that they were unable to recognize any consistent difference be tween "T." euapertura and "T* " prasaepis. This conclu sion— that the two are synonymous--!s accepted here as well. Blow (1969) differentiated his Globigerina prasaepis from Jenkins's taxon by stating that the latter has "a restricted aperture and a well developed apertural lip" (p. 382). No apertural lip is visible in the holotype illustration of "T." euapertura, however, nor is one des cribed in the definition of this species (Jenkins, i960). The apertures in these species appear to be equally re stricted, and there is no clear basis for differentiating them. Stainforth (1974) suggested that "T." prasaepis should be considered as "merely a low—apertured variant of 262 G. ampliapertura" (p. 26l), but "T." euapertura maintains a consistent morphology over a long interval subsequent to ttie extinction of typical "T.n ampliapertura. Blow and Banner (1962), indeed, documented tbe evolution "T." euapertura from "T." ampliapertura during tbe Late Eocene and Early Oligocene, Stratigraphic Range: MT." euapertura is present at all three sites and ranges from the Cassigerinella chipolensis — Pseudohastigerina barbadoensis Zone at Site 219 through upper part of the "T." kugleri Zone at Site 237. “Turborotalia” kugleri (Bolli) Globorotalia kugleri Bolli, 1957b, PI. 28, Figs. 5* 6. Globorotalia (Turborotalia) kugleri Bolli, Blow, 1969, PI. IO, Pigs. l-3> PI. 38, Figs. 1-4. Globorotalia (Turborotalia) kugleri Bolli, Bronnimann and Resig, 1971, PI. 39, Figs. 1, 3, 5. Remarks: This distinctive and restricted species seems to be strongly resistant to test dissolution (Jen kins and Orr, 1972). Stratigraphic Range: This species is limited to the "Turborotalia" kugleri Zone at Site 237. 263 "Turbo rotalia” mendacis (b Ioyt) Globorotalia (Turborotalia) mendacis Blow, 1 9 6 9, PI. 38, Figs. 5-9. Globorotalia (Turborotalia) mendacis Blow, Bronnimann and Resig, 1971, PI* 39, Figs. 6-8. Remarks: "Turborotalia" mendacis most closely re sembles "T." pseudokugleri. from vdiich it is differentiated by tbe bigber spire and resulting increased convexity of tbe spiral side. Botb of tbese species differ from "T. " kugleri in having straight rather than strongly recurved dorsal intercameral sutures. Stratigraphic Range; ”T." mendacis ranges from tbe upper part of tbe Globoquadrina binaiensis Zone through tbe top of the "T." kugleri Zone at Site 237* "Turborotalia1 1 opima nana (Bolli) Globorotalia opima nana Bolli, 1937b, PI. 28, Fig. 3* Globorotalia (Turborotalia) opima nana Bolli, Blow, 1969, PI. 39, Fig. 1. Turborotalia (Turborotalia) opima nana (Bolli), Fleisher, 1974a. PI* 19, Pig* 11. Remarks: The evolution of this form to "T, 1 1 bella has been discussed above. Stratigraphic Range: A single specimen found in Sample 219-16-CC (Turborotalia cerroazulensis Zone) may be 264 downhole contamination* Otherwise, the species ranges from Cassigerinella chipolensis - Pseudohastigerina barba- doensis Zone at Site 219 through the upper part of the "T." kugleri Zone at Site 237* This is somewhat higher than the top of the range recorded by Blow (1969)# "T. " opima nana is also present throughout the Oligocene sequence recovered at Site 220. "Turborotalia" opima opima (Bolli) Globorotalia opima opima Bolli, 1957h, PI. 28, Figs. 1, 2. Globorotalia (Turborotalia) opima opima Bolli, Blow, 1969* PI. 39, Fig. 3. Turborotalia (Turborotalia) opima opima (Bolli), Fleisher, 197^-a, PI." 19, Fig. 12. Strati graphic Range; "T. , f opima opima was found only within the "T." opima opima Zone at Sites 220 and 237* “Turborotalia” pseudokugleri (Blow) Globorotalia cf. kugleri Bolli, 1957h, PI. 28, Fig. 7, not Figs. 5, 6. Globorotalia (Turborotalia) pseudokugleri Blow, 1969, PI. 10, Figs. k-6 ; PI. 39, Figs. 5, 6. Globorotalia (Turborotalia) pseudokugleri Blow, Bronnimann and Resig, 1971, PI. 39, Fig. 2. Remarks: See comments above for “Turborotalia” mendacis. 265 Stratigraphic Range: Tliis species ranges from the upper part of the Globoquadrina binaiensis Zone (slightly lower than the base of the range of "T. 1 1 mendacis) to the middle of the "T. 1 1 kugleri Zone, “Turborotalia” pseudomayeri (Bolli) Plate 11, Figures 7> 8 Globorotalia pseudomayeri Bolli, 1957c, PI. 37> Fig. 17. Stratigraphic Range: Very rare specimens were re covered from a number of horizons within the Morozovella coronata - M. aragonensis Zone at Site 237* "Turborotalia” sp. 1 Turboro talia (Turboro talia) sp. 1, Fleisher, 197^a-> PI* 21, Fig. 6. Remarks: This small and generalized species has a relatively wide distribution at Site 237* Typically there are four and one—half to five chambers in the final whorl, and occasionally the final chamber may be small and abor tive. The chambers are closely appressed and not strongly distinct, but the periphery is broadly rounded. There is usually an apertural lip or rim which may be extended (as on the specimen illustrated by Fleisher, 197^a) into a broad flap. Stratigraphic Range: "Turborotalia" sp. 1 is re- 266 stricted to the Truncorotaloides pseudodubius Zone at Site 219, but ranges from that level as low as the upper portion of the Globigerinatheka senni Zone at Site 237- GENUS Turborotalita Blow and Banner, 1962 Type Species: Truncatulina humi1is Brady* Remarks: As originally defined, Turborotalita was characterized by the presence of a bulla with accessory sutural apertures covering a primary umbilical to extra- umbilical aperture. This definition is difficult to apply consistently, in that it separates very similar species which appear to be very closely related. T. humilis and 2* clarkei are virtually identical in size, overall test / 1 1 form, pore distribution, and spine development (see Rogl and Bolli, 19739 PI* ^ 9 Figs. 13-15; Banner and Blow, 1960b, PI. 8, Fig. l). They differ, however, in the degree of modification of the final chamber* A more satisfactory basis for the recognition of Turborotalita is a combination of overall form and wall texture. All known species are small and compact forms with closely appressed chambers. Much of the wall is im perforate, but relatively large pores are concentrated near the periphery, and in at least one species (T. clarkei), are present as accessory apertures along the spiral suture (Rogl and Bolli, 1973» Fleisher, 197^b). 267 Very short spinelike projections are also concentrated along the periphery and are quite visible in SEM photo graphs (Fleisher, 1974b, PI. 2, Figs. 4-6); they are clearly present in the type species as well (Banner and Blow, 1960b, PI. 8; Jenkins and Orr, 1972, PI. 4l, Figs. 3, 4). The aperture, whether or not covered by a bulla, consists of an elongate umbilical to extra-umbilical slit. Turborotalita clarkei (Rogl and Bolli) Globigerina clarkei Rogl and Bolli, 1973* PI* 4, Figs. 13- 15* Turborotalita "quinqueloba” (Natland), Fleisher, 1974a, P. 1037. Turborotalita "quinqueloba1 1 (Natland), Fleisher, 1974b, PI. 2, Figs. 4—6. Remarks: Fleisher (1974b) discussed the morphology and distribution of this species. The range is not known, and the occurrence here may represent contamination. T. clarkei seems to be a warm—water equivalent to the cool- water Neogene species ?T. quinqueloba. Stratigraphic Range: Turborotalita clarkei was ob served only in the upper Catapsydrax dissimilis and Globigerinatella insueta Zones at Site 237. 268 II ? Turboro talita primitiva Bronmmann and Resig t > Turborotalita primitiva Bronnimann and Resign, 1971* PI* 26, Figs. 5-9* Remarks: This minute species appears to be the descendent of Globanomalina laccadivensis; Fleisher (197^+a) discussed the morphological basis for distinguish ing the two forms* ?T* primitiva is probably intermediate, phyletically, between Globanomalina and Turborotalita* It resembles the former in the distribution of pores over much of the ventral test surface, but there is an indica- I ! tion in Bronnimann and Resig*s illustrations of initial restriction of pore distribution toward the peripheral regions of the test* The degree of peripheral spine development is unclear in these forms because of the thickened wall* After further study it may be desirable to refer ?T. primitiva to Globanomalina * but this step has not yet been taken. Stratigraphic Range: ?Turborotalita primitiva is limited, at Site 237* to Sample 237-19-1* 79-81 cm (Globigerinatella insueta Zone)• At Site 220, however, it ranges from the uppermost sample of the "Turborotalia" opima opima Zone through the Globoquadrina binaiensis Zone. 269 PLATES PLATES Multiple illustrations of a single species represent different specimens unless otherwise indicated, "D" is a measurement of the maximum dimension of the test as viewed in the illustrated orientation. All illustrated specimens are in the collection of the author, Plate 1 Figures 1, 2: Acarinina boudreauxi Fleisher, Both illus trations are of the holotype, Sample 219—19—6, 51—53 cm, GTobigerinatheka curryi — G. euganea Zone, Middle Eocene, Fig, 1: Ventral view, X 165* D = 0,35 mm. Fig, 2: Dorsal view, X 165# D = 0,35 mm. Figures 3» 4, 5* Acarinina colomi (Bermudez), All from Sample 237-30-2, 64-66 cm, Globigerinatheka senni Zone, Early Eocene, Fig* 3s Ventral view, X 100, D = 0.56 mm. Fig, 4: Dorsal view, X 100. D = 0.58 mm. Fig. 5i Apertural view, X 100. D = 0.50 mm. 271 Figures 6, 7» 8: Acarinina planodorsalis Fleisher. All are illustrations of the holotype, Sample 219-20-4, 52.54 cm, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Fig. 6: Ventral view, X 165* D = 0.35 mm. Fig. 7s Dorsal view, X 165* D = 0.35 mm* Fig. 8: Apertural view, X 165* D = 0.34 mm. -A* PLATE 1 273 Plate 2 Figures 1, 2, 3 s Acarinina aff. A. punctoearinata Fleishe Fig, 1: Ventral view, X 100, D = 0.3^ nira. Sample 237“27-l> 79-81 cm, Globigerinatheka curryi - G, euganea Zone, Middle Eocene, Fig, 2s Dorsal view, X 100, D = 0,62 mm. Sample 237—27-5* 79—81 cm, Morozovella coronata - M, aragonensis Zone, Middle Eocene, Fig, 3s Apertural view, X 100, D = 0,30 mm. Sample 237—27—5* 79—81 cm, Morozovella coronata - M . aragonensis Zone, Middle Eocene, Figures 4, 3s Acarinina sp, 1, Both from Sample 237-27-6 74—76 cm, Morozovella coronata — M. aragonensis Zone, Middle Eocene. Fig, 4: Side view, X 200, D = 0,29 nun, Fig. 3s Ventral view, X 200. D = 0.27 mm. Figure 6: Catapsydrax stainforthi Bolli, Loeblich, and Tappan, ventral view, X 100. D = O.33 mm. Sample 237-19-6, 79-81 cm, Catapsydrax dissimilis Zone, Early Miocene. Figures 7> 8: Catapsydrax sp. 1. Both from Sample 237-25-^* 79-81 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 7s Ventral view, X 100. D = 0.32 mm. Fig. 8: Side view, X 100. D = orientation, the aperture is rounded chamber on the right 0.30 mm. In this to the right; the small is the apertural bulla. 273 PLATE 2 276 Plate 3 Figures 1, 2: Clavigerinella .jarvisi (Cushman) . Sample 237-30-2, 79-81 cm, Globigerinatheka senni Zone, Early Eocene# Fig# Is Side view, X 100; D = 0.87 mm. Fig. 2: Detail of wall of final chamber, same specimen as Fig. 1. X 1000. Note the similarity to the wall of Hantkenina aragonensis (PI. 7* Fig. 2), and to a lesser extent, Protentella cf. P. nicobarensis (PI. 8, Fig. 2). Figures 3> ^ s Globanomalina laccadivensis Fleisher. Both from Sample 219-18-2, Globigerinatheka semiinvoluta Zone, Late Eocene# Fig. 3 5 Ventral view of holotype, X 413. D = 0.12 mm. Fig. 4: Edge view of paratype, X 415. D = 0.11 mm. Figure 3 5 Globigerina angulisuturalis Bolli, ventral view, X 200. D = 0.24 mm. Sample 237-22-CC, Globoquadrina binaiensis Zone, Late Oligocene. Figure 6: Globigerina anguliofficinalis Blow, ventral view, X 200. D = 0.27 nun. Sample 237-21-1, "Turborotalia” kugleri Zone, Early Miocene. Figure 7» "Globigerina” nepenthoides (Bronnimann and Resig), ventral view, X 200. D = 0.26 mm. Sample 237—19—1* 79-81 cm, Globigerinatella insueta Zone, Early Miocene. PLATE 3 Plate h Figures 1, 2: "Globigerina” voodi connecta (Jenkins). Sample 237-21-1, 79-81 cm, "Turborotalia" kugleri Zone, Early Miocene. Fig. 1: Ventral view, X 200. D = 0.27 mm. Fig. 2: Detail of wall of antepenultimate chamber, same specimen as Fig. 1, X 1000. The well- developed pore pits characterize this group of species. Figure 3 s "Globigerina" pseudodruryi (Bronnimann and Resig), ventral view, X 200. D = 0.31 mm. Sample 237—19—1, 79-81 cm, Globigerinatella insueta Zone, Early Miocene. Figures 4, 5s Globigerinatheka curryi Proto Decima. Both from Sample 237—25— 79-81 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. hi Side view, X 50# D = 0.68 mm. Fig. 5s Dorsal view, X 50# E> = 0.68 mm. Figures 6, 7f 8: Globigerinatheka subconglobata (Chalilov). All from Sample 237-27-1* 79-81 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 6: Dorsal view, X 50. D = 0.5^ mm. Fig. 7s Top view, X 50* D = 0.53 mm. Fig. 8: Side view, X 50» D = 0.60 mm. 279 Figures 9» 10, U s Globigerinatheka euganea Proto Cecima and Bolli. All from Sample 237-25-1, 79-81 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene * Fig. 9s Side view, X 50. D = 0.59 mm. Fig. 10: Dorsal view, X 50. D = O.67 mm. Fig. 11: Top view, X 50. D = O.63 mm. 2 80 ». tl' x/.J PLATE 4 281 Plate 5 Figures 1, 2: Globigerinatheka bigginsi (Bolli). Fig. Is Side view (apertural), X 100. D = 0.35 mm. Sample 237-27-CC, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Fig. 2: Side view (dorsal), X 100. D = 0.40 mm. Sample 237-28-3, 79-81 cm, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Figure 3? G1obigerinatheka rubriformis (Subbotina), side (apertural) view, X 50* D = 0.62 mm. Sample 237-28-4, 79-81 cm, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Figures 4, 5s Globigerinatheka senni (Beckmann). Both from Sample 219-19-6, 51-53 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 4: Side view, X 165. D = 0.34 mm. Fig. 5* Apertural view, X 165* D = 0.27 mm. Figures 6, 7s Globigerinatheka cf. G. senni (Beckmann). Both from Sample 237-24-4, 79-81 cm, Truncorota- loides pseudodubius Zone, Middle Eocene. Fig. 6: Side (apertural) view, X 100. D = 0.52 mm. Fig. 7s Side (lateral) view, X 100. D = O.56 mm. Figure 8: Globigerinita boweni Bronnimann and Resig, ventral view, X 165. D = 0.17 mm. Sample 219-14-4, 2 82 55-57 cm, Globigerinatella insueta Zone, Early Miocene, Figures 9* 10: Globigerinoides altiaperturns Bolli, Both From Sample 219-1^-^» 55-57 cm, Globigerinatella insueta Zone, Early Miocene, Fig, 9s Ventral view, X 165# B = 0,32 mm. Fig, 10: Dorsal view, X 165. D = 0.35 nim. 283 PLATE 5 28 k Plate 6 / Figure 1: Globoquadrina globularis Bermudez, ventral view, X 100. D = O.56 mm. Sample 237—19—CC, Cat a— psydrax dissimilis Zone, Early Miocene. Figures 2, 3s Globoquadrina pozonensis Blow. Sample 237-20-3* 79-81 cm, "Turborotalia” kugleri Zone, Early Miocene. Fig. 2: Ventral view, X 100. D = 0.32 mm. Fig. 35 Detail of aperture, same specimen as Fig. 2, X 500. Note tbe presence of a small but distinct lip. Figure 4s Globoquadrina baroemoensis (LeRoy), ventral view, X 100. D = 0.58 mm. Sample 237-19-1, 79-81 cm, Globigerinatella insueta Zone, Early Miocene. Figures 5* 6: Morozovella bandyi Fleisher. Botb illustra tions are of the holotype, Sample 219-19—6, 51-53 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 5: Ventral view, X 165* D = 0.35 nun. Fig. 6: Dorsal view, X 165* D = 0.35 mm. Figures 7, 8: Morozovella spinulosa (Cushman). Both from Sample 237—28—3* 79—81 cm, Morozovella coronata — M. aragonensis Zone, Middle Eocene. 285 Fig* 7: Ventral view, X 100. D = 0.55 mm. The small and indistinct umbilicus distinguishes this species from M. coronata (PI. 7* Figs. 3* 5) • Fig. 8s Dorsal view, X 100. D = 0.50 mm. The early chambers of the final whorl are broken. 286 PLATE 6 Plate 7. Figures 1, 2: Hantkenina (Hantkenina) aragonensis Nuttall. Sample 237-28-6, 79-81 cm, Morozovella coronata - M,aragonensis Zone, Middle Eocene, Fig. Is Side view, X 75; D = 1.04 mm. Fig. 2: Detail of* wall of final chamber, same specimen as Fig. 1, X 2000. Interpore ridges are strongly developed, but flat-bottomed pore pits are absent. Figures 3* 4, 5• Morozovella coronata Blow. All from Sample 237-29-2, 52-54 cm, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Fig. 3? Ventral view, X 100. D = 0.52 mm. Fig. 4: Apertural view, X 100. D = 0.49 mm. Fig* 5s Dorsal view, X 100. D = 0.55 *nm. Figures 6, 7s Morozovella sp. 1. Both from Sample 237-25-1* 79-81 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 6: Ventral view, X 100. D = 0.42 mm. Fig. 7s Dorsal view, X 100. D = 0.44 mm. 288 PLATE 7 289 Plate 8 Figures 1, 2: Protentella cf. P. nicobarensis (Srinivasan and. Kennett), Sample 237-21-1, 79-81 cm, "Turboro- talia” kugleri Zone, Early Miocene. Fig. Is Side view, X 200. D = 0.30 mm. Fig. 2: Detail of wall of final chamber, X 2000. This wall type contrasts with that of Clavatorella bermudezi. as illustrated by Fleisher (1974a). , " x Figure 3: Subbotina eocaena (Gumbel), ventral view, X 100. D = 0.53 nun. Sample 237-30-4, 79-81 cm, Globigeri- theka senni Zone, Early Eocene. Figures 4, 5* Subbotina sp. 1. Both from Sample 237—23—6, 79—81 cm, Globigerinatheka semiinvoluta Zone, Late Eocene. Fig. 4: Ventral view, X 50. D = 0.80 mm. Fig. 5: Ventral view of specimen with broken bulla, X 50. D = 0.70 mm. Figures 6, 7» 8: Subbotina kiersteadae Fleisher. All from Sample 219-19-6, 51-53 cm, Globigerinatheka curryi - G. euganea Zone, Middle Eocene. Fig. 6: Ventral view of holotype, X 165. D = 0.43 mm. Fig. 7s Side view of holotype, X 165* D = 0.42 mm. Fig. 8: Ventral view of small paratype, X 165. D = 0.35 mm. 290 PLATE 8 291 Plate 9 Figures 1, 2: Subbotina minima (Jenkins), Sample 237—23-4, 79—81 cm, Turborotalia cerroazulensis Zone, Late Eocene. Fig. Is Ventral view, X 100. D = 0.33 nun. Fig. 2: Detail of aperture, same specimen as Fig. 1, X 500. Figures 3* 4: Subbotina utilisindex (Jenkins and Orr). Sample 237-23-1* 79-81 cm, Turborotalia cerroazulen sis Zone, Late Eocene. Fig. 3: Ventral view, X 100. D = 0.39 mm. Fig. 4: Detail of aperture, same specimen as Fig. 3* X 500. The absence of an apertural lip distinguish es this species from S. minima and £>. angiporoides. Figure 5s Tenuitella gemma (Jenkins), ventral view, X 415# D = 0.19 mm. Sample 219-15-2, 51-53 cm, Cassi- gerinella chipolensis — Pseudohastigerina barbado- ensis Zone, Early Oligocene. 292 PLATE 9 Plate 10 Figures 1, 2, 3: Tenuitella angustiumbilicata (Bolli), Fig* Is Ventral view, X 200. D = 0.22 mm. Specimen is from the type locality of this species, Sample horizon Bo 291A of Bolli (l957h). Fig. 2: Detail of wall of final chamber, same speci men as Fig. 1, X 2000. The microperforate wall texture is apparent in this illustration; pores comparable to those in Globigerina bulloides (Fleisher, 197^a) are not present. Fig. 3? Ventral view, X 200. D = 0.25 nun. Sample 237—19—1* 79—81 cm, Globigerinatella insueta Zone, Early Miocene. Figures 5* 6: Tenuitella praestainforthi (Blow). Sample 237—20—5* 79—81 cm, "Turborotalia1 1 kugleri Zone, Early Miocene. Fig. 5: Ventral view, X 200. D = 0.26 mm. Fig. 6: Detail of bulla and wall of final chamber, same specimen as Fig. 5* X 1000. The test wall is clearly microperforate in texture. 29^ PLATE 10 Plate 11 / it Figures 1, 2: Tenuitella cf. T. nkbrowni (Bronniraann and Resig), Both, from Sample 237-19-49 79—81 cm, Cata- psydrax dissimilis Zone, Early Miocene, Fig. 1: Ventral view, X 300. D = 0.12 mm. Fig. 2: Dorsal view, X 300. D = 0.11 mm. Figure 3s Truncorotaloides cf. T. topilensis (Cushman), ventral view, X 100, D = 0,4l mm. Sample 237—27—6, 74-76 cm, Morozovella coronata - M. aragonensis Zone, Middle Eocene. Figures 4, 5s "Turborotalia1 1 bella (Jenkins). Both from Sample 237—19—1, 79—81 cm, Globigerinatella insueta Zone, Early Miocene. Fig. 4: Ventral view, X 100. D = 0.34 mm. Fig. 5s Apertural view, X 100. D = O.36 mm. Figures 6, 9s "Turborotalia" aff. "T." bella (Jenkins). Both from Sample 237-19-6, 79-81 cm, Catapsydrax dissimilis Zone, Early Miocene. Fig. 6: Ventral view, X 100. D = O.38 mm. Fig. 9s Apertural view, X 100. D = 0.40 mm. Figures 7> 8: "Turborotalia" pseudomayeri (Bolli). Both from Sample 237-27—CC, Morozovella coronata - M. aragonensis Zone, Middle Eocene. 296 Fig. 7 Fig. CO Ventral view, X 100. I . ) = 0.37 Apertural view, X 100. D = 0#' mm. 1 mm. 297 PLATE 11 REFERENCES 2 99 REFERENCES The relevant portions of references marked with an asterisk (*) were examined only in the Catalogue of Foraminifera (American Museum of Natural History, New York). Akers, W. H., 1955* Some planktonic foraminifera of the American Gulf Coast and suggested correlations with the Caribbean Tertiary: Jour, Paleont., vol. 29* no, 4, p, 66l. 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Printing Office), P. 573-378. 323 APPENDIX Distribution of planktonic foraminiferal species in Lower Eocene to Lower Miocene sediments recovered at Deep Sea Drilling Project Sites 219» 220, and 237* 326 O LIG O C E N E S M IO CENE Early < Early Cassigerinella chipolensis- > . . . . . _ . . . . i . . > Globigerinatella insueta Pseudohastigenna barbadoensis < 15 15 15 15 15 15 15 16 16 16 16 16 16 2 3 4 5 6 CC 1 105-107 0 O) Ol U M 51-53 51-53 51-53 51-53 51-53 51-53 48-50 54-56 52-54 52-54 51-53 51-53 52-54 46-48 55-57 51-53 51-53 46-48 47-49 55-57 52-54 54-56 • O O O O O O • O • O O O O O • O ■ • ■ O O ■ ■ ■ ■ ■ ■ ■ ■ O O ■ • • • O O O • O O O O O O O O • • • O • • ■ ■ ■ ■ ■ • ■ ■ ■ ■ ■ ■ ■ ■ O O ■ ■ • • ■ • • O O • • ■ O O ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ O O ■ ■ ■ ■ ■ ■ ■ ■ • • • ■ ■ • O • O O O O O O • O O O O • AGE ZONE CORE SECTION SAMPLE INTERVAL w H m Cassigerinella chipolensis Chiloguembelina spp. Globanomalina laccadivensis G. pseudoscitula Globigerina praebulloides occlusa G. praebulloides s.s. " Globigerina" pseudodruryi Globigerinatella insueta Globigerinatheka semiinvoluta G. tropicalis G. mexicana G. senni G. barri G. index G. curryi G. lu terbacheri G. subconglobata G. higginsi Globigerinita bo weni Globigerinoides diminutus G. obliquus s.s. G. praesicanus G. subquadratus G. quadrilobatus s.s. G. altiaperturus Globoquadrina altispira s.s. G. baroemoenensis G. debiscens s.s. G. larmeui obesa G. binaiensis G. debiscens praedehiscens G. galavisi G. tapuriensis G. tripartita G. pseudovenezuelana Abundance: o Rare Few Common 32? M i d d l e Morozovella coronata - M. aragonensis E O C E N E Truncoro taloides pseudodubius 19 20 20 20 20 20 20 20 21 21 21 21 21 to 0 ( 0 ( 0 ( 0 ( 0 0 3 0 0 0 0 0 0 0 9 17 17 18 18 2 3 4 5 6 CC 1 2 3 4 CC 1 100-102 o o C T > 3 4 5 6 CC 1 2 3 4 5 5 CC 1 2 Ji. co no 00 00 C T > o o 51-53 5 1 53 52-54 50-52 5 1 53 5 1 53 5 1 53 52-54 . 49-51 f 51-53 1 53-55 51-53 51-53 51-53 42-44 5 1 53 52-54 50-52 52-54 51-53 52-54 55-57 52-54 51-53 51-53 • • o • • o o ■ ■ • ■ ■ ■ • ■ ■ ■ o o • o o o o o o o O • o o • o o o o o o o o o o o • o o o o o o • • • • • o • ■ • o o o o o o o o o • o o o o o • • o ■ o o o • o • o o o o • O o o o o o o o • • • • o o • • • o • ■ • ■ ■ ■ • • • • • o o • • o ■ • • o o o o • • • o • o o o o o o o • o • • o o o o • • • • • • o o o o o o o o L a te Turborotalia cerroazulensis AGE ZONE CORE SECTION SAMPLE INTERVAL A car in ina bou dreaux i A. p/anodorsa/is A. bullbrooki A. mattseensis wartsteinensis A punctocarinata Cassigerinella chipolensis Catapsydrax dissimilis ciperoensis C. perus C. unicavus unicavus C. unicavus primitivus C. martini C. africanus C. globiformis Chiloguembelina spp. G/obanomalina laccadivensis G. pseudoscitula Globigerina praebulloides occlusa G. praebulloides s.s. "Globigerina" pseudodruryi Globigerinatella insueta Globigerinatheka semiinvoluta G. tropical is G. mexicana G. senni G. barri G. index G. curryi G. luterbacheri G. subconglobata G higginsi Globigerinita boweni Globigerinoides diminutus G. obliquus s.s. G. praesicanus G. subquadratus G. quadri/obatus s.s. G. altiaperturus Globoquadrina altispira s.s. G. baroemoenensis G. debiscens s.s. G. larmeui obesa G. binaiensis G. dehiscens praedehiscens G. galavisi G. tapuriensis G. tripartita G. pseudovenezuelana 1 Globigerinatheka semiinvoluta 2 Globigerinatheka curryi-G. euganea Abundance: O Rare Few Common 328 O L IG O C E N E < M IO C E N E E arly c Early Cassigerinella chipo/ensis- Pseudohas tigerina barbadoensis | Globigerinatella insueta 1b 15 15 15 15 15 15 16 16 16 16 16 16 13 13 13 13 13 13 14 14 14 14 14 14 14 2 3 4 5 6 CC 1 1 2 3 4 5 6 CC 5 1 53 5 1 53 5 1 53 5 1 53 5 1 53 5 1 53 48-50 54-56 5 2 54 5 2 54 5 1 53 51-53 46-48 47-49 55-57 5 2 54 5 4 56 105-107 52-54 46-48 55-57 5 1 53 5 1 53 ■ ■ ■ ■ ■ ■ ■ • ■ • O • • O 0 0 0 O O O • O O • • • • • O ■ • • • ■ • • O O • O • 0 0 0 • • • 0 0 • • • O ■ • • 0 0 0 0 • O • • ■ • ■ ■ ■ ■ • • • ■ ■ ■ ■ ■ ■ • • 0 • ■ • • • O O • • O O 0 0 0 0 0 0 0 • 0 • • 0 0 0 0 • • • • • • ■ ■ 0 0 • 0 • ■ ■ 0 0 ■ 0 • • 0 0 • AGE ZONE CORE SECTION SAMPLE IN T E R V A L r o to 00 Globorotalia (F.) peripheroronda Globorotalia (G.) archeomenardii Globorotalia (H.) scitu/a praescitu/a Globorotaloides suteri G. turgidus Hantkenina (C.l inflata Hantkenina (H.) alabamensis H. (H.) aragonensis H. (H.) mexicana Morozovella coronata M. bandyi M. aragonensis s.s. M. lehneri Neogloboquadrina continuosa N. siakensis Pseudohastigerina barbadoensis P. micra P. wilcoxensis Subbotina winkleri S. angiporoides Tenuitella angustiumbilicata T. clemenciae T. gemma Truncorota/oides a ff. T. collacteus Turborotalia pseudoamp I iapertura T. cerroazulensis s.s. T. cerroazulensis cocoaensis T. cerroazulensis cunialensis "T. “ ampliapertura Abundance: o Rare • Few ■ Com m on 329 M iddle Morozovella coronata- M. aragonensis EO C EN E Truncoro ta/oides pseudodubius 19 20 20 20 20 20 20 20 21 21 21 21 21 C O 18 18 18 18 18 19 19 19 19 19 17 17 18 18 C T > 3 4 5 6 CC 1 2 3 4 5 5 CC 1 2 ■ U G J ro 1 134-136 CC 00-102 51-53 51-53 52-54 50-52 51-53 51-53 51-53 52-54 49-51 | 51-53 53-55 51-53 51-53 51-53 42-44 51-53 52-54 50-52 52-54 51-53 52-54 55-57 52-54 51-53 51-53 • o o o • o o o o o o o • • • • o • o o o o o • • • o o • o o o • • o • • o • • • • ■ ■ • • • • • • • • • • o • o o • o o • • o o ■ o o o o o o o o • o o • • • • • • • o • ■ • • • • o • o o o o o o • • • o • • • • o • • ■ • • • • o o o o • • o o o o o • o o o o • • o • o o o o o • • o • o • o o o o o • o o o • ■ • o o o o Late E Turborotalia cerroazulensis AGE ZONE CORE ro t o SECTION SAMPLE IN TE R V A L Globorotalia (F.) peripheroronda Globorotalia (G.) archeomenardii Globorotalia (H.J scitula praescitula Globorotaloides suteri G. turgidus Hantkenina (C.) inf lata Hantkenina (H.) alabamensis H. (H.) aragonensis H. (H.J mexicana Morozovella coronata M. bandy i M. aragonensis s.s. M. lehneri Neogloboquadrina continuosa N. siakensis Pseudohastigerina barbadoensis P. micra P. wi/coxensis Subbotina winkleri S. angiporoides S. Unaperta S. eocaenica S. eocaena S. kiersteadae Tenuite/la angustiumbilicata T. clemenciae T. gemma Truncorotaloides all. T. collacteus T. collacteus T. pseudodubius Turborotalia pseudoamp/iapertura T. cerroazulensis s.s. T. cerroazulensis cocoaensis T. cerroazulensis cunialensis T. pomeroli T. patagonica T. boweri "Turborotalia" birnageae T . " euapertura 1 Globigerinatheka semiinvoluta 2 Globigerinatheka curryi-G. euganea Abundance: O Rare Few I Com mon 330 E O C E N E AGE Early ZONE G lo b ig e rin a th e k a senm G lo b o q u a d rin a b m a ie n s/s M. a ra go ne nsis M. ara go ne nsis CORE SECTION SAMPLE IN TE R VA L p la n o d o rs a h s s o ld a d o e n s is a n g u lo sa a p a n th e s m a p s e u d o to p H e n s is C assig e rin e lla c h ip o le n s is C a ta p s y d ra x d is s im il/s s.s. C. d /s s im jfis c ip e ro e n s /s C. u n ic a v u s p r im it iv u s C. p e ru s C h ilo g u e m b e h n a c u b e n sis G lo b a n o m a iin a p s e u d o s c itu la G lo b ig e rin a c f. G. a n g u l/s u tu ra lis G. a n g u h s u tu ra h s " G lo b ig e rin a " c f. "G . " w o o d i s.s. G lo b ig e rin a th e k a in d e x G. s u b c o n g /o b a ta G. k u g te ri G h ig g m s i G (jfo h o sa G w A b u n d a n c e : o R are • F e w ■ C o m m o n 331 E O C E N E O L IG O C E N E E a rly M id d le L a te M o ro z o v e lla fo rm o s a - M. ara go ne nsis G lo b ig e rin a th e k a senni M o ro z o v e lla c o ro n a ta - M. ara gonensis " T u r b o r o ta lia " o p tm a o p im a G lo b o q u a d rin a b in a /e n sis CO CD CD vJ J) 13 13 13 14 14 14 14 15 15 15 15 15 15 12 12 12 12 12 12 13 13 01 01 0L 6 £* CO o 2 CC 1 2 2 3 4 5 CC 1 2 CC 1 2 CC 6 3 / 0 5 5 57 5 0 52 o o o o o o o o tr 70 72 70 72 70 72 70 72 70 72 70 72 o o o o o o o o c o o o S o c o o o o o o o O o o • o o O O • o • • o o o o o o • • o o o • o o o o • • o o • o o • o o o • o o o o o o o • ■ ■ • • ■ • ■ ■ • • ■ o o o o • ■ ■ • ■ ■ • ■ o O • o o o o • o o o o o • • o o o o • o o o o o o o o o o o o o o o o o o O o o o o • o o • o o o o o o o o o o o • o o • ■ o • o o o o o o o • • ■ O • o • ■ • ■ ■ ■ ■ ■ ■ ■ • ■ ■ ■ ■ ■ ■ o o o o • o o o • o o o o o o o o o • o o • • o • • • • o • o o • o o o o o o o o o o o o • * • • • ■ ■ • • • o ■ • • o • • • o • o o o o o o o • • • o o o o • o o o o • • • • ■ • • • o o • • • • o o o o o o o • o o O • o • o o o o o o o • o o o O O AGE ZONE SECTION SAMPLE IN TE R VA L G lo b o ro ta lo n /e s M /te r/ G tu rg id u s H a n tk e n in a (H .) ara go ne nsis M o ro z o v e lla ara go ne nsis s.s. M b a n d y I M . c o ro n a ta M. le b n e ri M ara go ne nsis caucas/ca N e o g io b o q u a d n n a siakensts P ro te n te lla c f. P. n ico b a re n s/s P s e u d o h a stig e rin a w i/c o x e n s is S n b b o ttn a g o rta n u S. a n g tp o ro id e s S u tih s m d e x .S e o cae na S eocaem ca S. k ie rste a d a e S. c o rp u /e n ta Tent i t te l/a angi is tn im h tl ica ta T . c (em en ciae T. p ra e s ta in fo / tin T. g e m m a T ru n c o ro ta lo /d e s c o lla c te u s T. p s e u d o d u b iu s J u rb o ro ta h a p a ra g o n ica T p o m e ro h T h o w e n " T u r b o r o ta lia " e u a p e rtu ra "T . " o p tm a na ns " T " o p tm a s.s “ T. " b o h v a n s n a T11rb o ro ta li ta p r /m t tiva Abundance: oRare 332 E O C E N E O L I G O C E N E M I O C E N E M id d le Late ( Turborotalia L a te E a r ly AGE Truncoro ta/oides pseudodubius 3 cerroazulensis < 2 Cloboquadrina binaiensis "Turborotalia" kug/eri 24 24 24 24 24 io m ro io ^ ^ co to 23 23 23 23 23 N O N O 21 21 21 21 21 22 22 22 20 20 20 20 20 20 20 21 21 1 9 1 9 19 19 19 19 co 3 4 5 6 CC 6 CC 1 2 tn 4 5 k C O NJ — * o o 3 4 5 6 CC 1 2 3 1 2 3 4 5 6 CC 1 2 2 3 4 5 6 CC - 7 9 81 7 9 8 1 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 7981 79-81 7981 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 7 9 81 79-81 I 79-81 | o o o o o o o o o o o o o o o o o o o • o • o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o ■ • ■ O o o o • • o ■ o o ■ o o • • ■ o o o o o o o o o o o o o o o o o o o o o o o o • o • o o • o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o Gatapsydrax dissimilis ZONE CORE SECTION SAMPLE INTERVAL sp. 1 mattseensis s.s. cf. A. bul/brooki mattseensis wartsteinensis co/omi soldadoensis s.s. pentacamerata Cassigerinella chipolensis stainforthi unicavus primitivus perus riveroae unicavus s.s. africanus martini s.s. sp. 1 praebulloides s. I. angu/iofficinalis ciperoensis ouachitaensis cf. G. angulisuturalis angulisuturalis officinalis Globigerinatella insueta 1 Globigerinatella insueta 2 "Turborotalia" opima opima Abundance: o R a re • Few ■C om m on 3 Globigerinatheka semiinvoluta 333 Early Globigerinatheka senni Morozovella coronata - M. aragonensis Globigerinatheka cu rryi- 4 G. euganea < 30 30 30 30 30 30 30 31 31 32 32 32 aa00000 C O C O C O C O C O C O C O M N jsjv|N jsl 25 25 25 25 25 25 25 26 26 26 26 26 27 Lee J _ . 6 CC 1 CC 2 3 1 5 101-103 co ro — ‘ 2 3 4 5 6 CC 1 2 3 4 5 6 CC 1 2 3 4 5 6 CC 1 2 3 4 5 6 CC 1 1 2 3 4 CC 1 94-96 74-76 59-61 14-116 95-97 64-66 79-81 79-81 84-86 79-81 79-81 79-81 74-76 79-81 8 9 91 79-81 79-81 79-81 79-81 8 9 91 52-54 24-26 94-96 89-91 8 9 91 79-81 79-81 79-81 79-81 79-81 79-81 09-111 79-81 79-81 79-81 79-81 • • • • • • o • • o o o • • o o • • • • • ■ • • • o o o • • • • o • o o • • • • o o ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ • • • • ■ • ■ ■ • • • o • • • o • • • • • • • o o • • ■ • o o o o o o o © o o o o o • o • • o o • o o o o o o o o • o o o • o • • • ■ ■ ■ • ■ • ■ ■ ■ o o • • • • • • • ■ ■ • ■ ■ ■ • ■ • ■ • ■ ■ ■ ■ ■ ■ • • ■ • • o o o o o o o o o o o • • • ■ • ■ • ■ • • • • • • • o o o o o o o o o o o o o o o o o o • o • • o o o o o o o o o o 6 o o o • o o o o o o • o o o o o o o o o ■ ■ • o o o o o o o o o o o • o ■ ■ ■ ■ • o o • • o o o o o o o o o o AGE ZONE CORE SECTIO N SAMPLE IN T E R V A L A c a r in in a b o u d r e a u x i A . p u n c t o c a r in a t a A . a f f. A . p u n c t o c a r in a t a A . p la n o d o r s a iis A . sp. 1 A . m a tts e e n s is s.s. A . c f. A . b u i i b r o o k i m a tts e e n s is w a r ts te in e n s is c o l o m i A . s o id a d o e n s is s.s. A . p e n t a c a m e r a ta C a s s ig e r in e lla c h ip o le n s is C a ta p s y d r a x p a r v u lu s C. d is s im if is c ip e r o e n s is C. d is s im i/ is s. s. C. s t a in f o r t h i C. u n ic a v u s p r i m it iv u s C. p e r u s C. r iv e r o a e C. u n ic a v u s s.s. C. a f r ic a n u s C. m a r t i n i s.s. C. sp. 1 C h iJ o g u e m b e lin a c u b e n s is C. m a r t i n i C la v ig e r in e lla a k e r s i C. j a r v is i G /o b a n o m a /in a fa c c a d iv e n s is G. p s e u d o s c itu la G lo b ig e r in a o b e s a G. p r a e b u llo id e s s. I. G. a n g u l i o f f i c i n a f i s G. c ip e r o e n s is G. o u a c h ita e n s is G. c f. G. a n g u lis u tu r a lis G . a n g u lis u t u r a lis G. o f f i c in a l i s " G lo b i g e r i n a " n e p e n t h o id e s " G . " p s e u d o d r u r y i " G . " w o o d i s.s. " G . " w o o d i c o n n e c ta G lo b ig e r in a t e lla in s u e ta A b u n d a n c e : O R a r e # F e w ■ C o m n 33b E O C E N E | O L IG O C E N E M IO C E N E AGE Middle Late ? Late E arly ?Truncorota/oides\ ^ [ £ pseudodubius / | Turborotalia cerroazulensis >2 Globoquadrina binaiensis "Turborotalia” kugleri Catapsydrax dissimilis 1 ZO NE 24 24 24 24 24 23 23 24 24 23 23 23 23 23 M 21 21 21 21 21 22 22 22 20 20 20 20 20 20 20 21 21 19 19 19 19 19 19 CO CORE 3 4 5 6 CC 6 CC 1 2 u i - C* CO N ) —» n n 3 4 5 6 CC 1 2 3 1 2 3 4 5 6 CC 1 2 2 3 4 5 6 CC S EC TIO N 7 9 81 7 9 81 7 9 8 1 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 79-81 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 79-81 7 9 8 1 79-81 7 9 81 79-81 79-81 79-81 7 9 81 79-81 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 79-81 7 9 81 7 9 8 1 7 9 81 SAMPLE IN T E R V A L ■ • Globigerina theka semi in vo/u ta • o o • • o • • G. tropicalis o G. luterbacheri G. senni • • • ■ ■ ■ ■ G. cf. G. senni • • o o o o G. barri o o G. rubriformis G. mexicana G. subcong/obata G. kugleri G. curry i G. euganea G index G. higginsi G/obigerinita glutinata s.s. G. glutinata ambitacrena G. uvula G. boweni G. glutinata parkerae Globigerinoides altiaperturus G. obliquus s.s. G. praesicanus G, quadrdobatus s.s. G. quadrdobatus immaturus G. quadrdobatus saccuhfer G. subquadratus G. trdobus G. primordius G. aff. G. sicanus G. diminutus Globoquadrina a/tispira s.s. G. baroemoenensis G. globosa G. venezuelana G. debiscens s.I. G. tripartita G. binaiensis G. globu/aris G. praedehiscens G. pozonensis G. sellii G. galavisi G. pseudovenezue/ana o o o o o o • • • • • • • ■ ■ ■ • • • ■ ■ • • o o • • • • • o • o o o • • ■ ■ • ■ ■ ■ ■ ■ ■ ■ ■ o o o o • • • • • o • o o o o o o o • • o • o o o o • ■ ■ ■ ■ ■ • o o • o o • • ■ o ■ • • • • • • o o o o o o o o o o o o o o • • • • • • o o o o o o o o • ■ • • • • • o o o • o o o o o o • • ■ • • o o o o o • o • • • • • • m • • • • • • • • • • • • • • o o o o o o o o o o o o o o o o o • • • • ■ ■ • • • o • • • o o o o o • • • ■ ■ ■ ■ ■ o o o o o • o o • o • o o • o • • • • • ■ • ■ • ■ • • • ■ o o o o o o o • • • o • • o • I 1 Globigerinatella insueta 2 "Turborotalia" opima optma 3 Globigerinatheka semiinvoluta Abundance: O Rare • Few ■ Common 335 Early Globigerinatheka senni Morozovella coronata -M . aragonensis Globigerinatheka c u rry i- G. euganea \ w c o c o w w y u w c o w c o u 27 27 27 27 27 27 28 28 28 28 28 28 28 29 29 29 29 29 29 29 25 25 25 25 25 25 25 26 26 26 26 26 27 3 1 1 4 116 C C 1 6 CC 1 CC 2 5 101 103 A CO ISJ - 2 3 4 5 6 CC 1 2 3 4 5 6 CC 1 2 3 4 5 6 CC 2 3 4 CC 1 1 109-111 1 2 3 4 5 6 CC 94-96 74-76 59-61 95-97 6 4 66 79-81 7 9 81 8 4 86 79-81 7 9 81 7 9 81 7 4 76 7 9 81 8 9 91 79-81 7 9 81 7 9 81 79-81 89-91 5 2 54 24-26 94-96 89-91 89-91 79-81 7 9 81 79-81 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 7 9 81 79-81 • O • O O O • O O O O O O O • O O O O O O O O • O O O O O O O O O O O O O O ■ O • O O • • O O O O O O • • O O O O • • O O O O O O O O O O O O O O O O O O O O O O O O O O O O AGE Z O N E CORE S E C T IO N SAMPLE INTERVAL G/obigerinatheka semiinvoluta G. tropica/is G. futerbachen G, senni G, cf. G. senni G. barri G, rubriform is G. mexicana G. subcong/obata G. kugleri G. curry i G. euganea G index G. higginsi G/obigerinita glutinata s.s. G. glutinata ambitacrena G. uvula G. boweni G. glutinata parkerae Globigerinoides altiaperturus G. ob/iguus s.s. G. praesicanus G. quadrilobatus s.s. G. quadrilobatus im m aturus G quadrilobatus saccuiifer G. subquadratus G. tri/obus G. prim ordius G. aff. G. sicanus Globoquadrina a/tispira s.s, G. baroemoenensis G. globosa G. venezuelana G. dehiscens s i. G. tripartita G. binaiensis G. globular/s G. praedehiscens G. pozonensis G. set Hi G. galavisi G. pseudovenezuelana Abundance: oRare 336 EOCENE O L IG O C E N E Late M IO C E N E Early AGE 1 Truncoro taloides > pseudodubius T u rb o ro talia cerroazulensis ' G lo b o q u ad rin a binaiensis ’T u rb o ro ta lia " kugleri Catapsydrax dissim iiis ZO NE N ) IO W IO OJ CO I V j N J I V J I V J I V J N 3 l V j h J l V j -“ - ■ O O O O O O O CD CD CD CD CD CD CORE O l A CO M c o m —• q O) tr -Ck w n j —‘Q cnoi^coro O O) cn co m SECTION Cp CD CD CD 00 00 00 CO CD CO CD 00 CO 00 CD CD CD CD CD 00 00 00 CO 00 SAMPLE IN T E R V A L G lo b o ro ta lia (F .) aff. G. p e riph eroronda G loborotaloides suteri G. turgidus H a n tk en in a (C .j in fla ta H a n tk en in a (H .) alabam ensis H. !H .) du m b tei H. (H .) aragonensis H. (H .) iongispina H. (H .) m exicana M orozovella coronata M. leh n eri M. sp. 1 M aragonensis M. b a n d y i M. spinulosa Neogl oboquadrina m a ye ri N. siakensis P ro te n te lla cf. P. nicobarensis Pseudohastigerina barbadoensis P. m icra P. wi/coxensis S u bbotina w in k le ri S. angiporoides S. eocaena S. m in im a S. utilisindex S. sp. 1 S. p ra e tu rritilin a S. corpu/enta S. eocaenica S. kiersteadae S. hagni S. inaequispira 1 G lobigerinatella insueta 2 " T u rb o ro ta lia " o pim a o p im a A b u n d an ce: O R a r e • F ew ■ C om m on 3 G lobigerinatheka sem iinvoluta 337 EOCENE Early Globigerinatheka senni Morozovella coronata-M . aragonensis Globigerinatheka curryi- G. euganea WWCOCOWyCOyWCOWW1 r o r o r o — » — » O O O o o o o N jro ro ro ro io ro ro ro ro ro ro ro ro ro ro ro ro ro ro (O(D(D(D©(D(OO300O3COCOCOO3sJ sJ nJ vJ sJ nJ 25 25 25 25 25 25 25 26 26 26 26 26 27 3 114-116 C C I 6 CC 1 CC 2 5 101-103 ■ C k C O ro — ‘ 1 2 3 4 5 6 CC 1 1 2 3 4 CC 1 94-96 74-76 59-61 95-97 64-66 79-81 79-81 84-86 79-81 79-81 79-81 74-76 79-81 89-91 79-81 79-81 79-81 79-81 89-91 52-54 24-26 94-96 89-91 89-91 79-81 ' 7 9 81 79-81 7981 7 9 81 79-81 109-111 79-81 79-81 79-81 7 9 81 o o o o o o o • o o o o o o • • o o o o o • o • o o o o o o o o o o o o o o o o o o o o o o • o o o o o o o o o o o o • • • • • • • • • • • o • • o o • • o o • • o o o « o o o o o o o o • ■ • • o o o o o o o o o o o • • • • ■ • • o o o o o o o o o o o o o o o o • • o o • o o o o o o o o o • o o o o • o o o o o o • • • o • o o • o o • • o o o • o o o • ■ • o • o • • o • • o o o o o o o o o o o o o o o o o • o o o o o o • o o o • o o o o o o • ■ ■ ■ ■ ■ ■ • ■ • • ■ • ■ • • • • • ■ • • • • • • ■ • • ■ • • • • ■ • o • o o o o o o o o o o o o o AGE ZONE CORE SECTION SAMPLE INTERVAL Globorotalia (F J aff. G. peripheroronda Gfoborotaloides suteri G. turg/dus Hantkenina (CJ inflata Hantkenina (H .) alabamensis H. (H .) dum biei H. (H .) aragonensis H. (H .) longisp/na H. (H .) mexicana Morozovella coronata M. fehneri M. sp. 1 M. aragonensis M. bandyi M. spinulosa Neogloboquadrina mayeri N. siakensis Protentella cf. P. nicobarensis Pseudohastigerina barbadoensis P. micra P. wilcoxensis Subbotina winkleri S. angiporoides S. eocaena S. m inima S. utiHsindex S. sp. 1 S. praeturriti/ina S. corpu/enta S. eocaenica S . kiersteadae S . hagni S. inaequ ispira Abundance: O Rare • Few ■ Common 338 E O C E N E < O L IG O C E N E M IO C E N E AGE M iddle Ldtp S Late Early > Truncorota/oi > pseudodubn des s 3 Turhcrotahd \ „ < erroasufensis \ * N Globoquadrina J binaiensis "Turborotafia" kugleri Catapsydrax dissinnlis 1 ZONE 24 24 24 24 24 \) m nj ^ w w W C O W O J C O ro ro 21 21 21 21 21 22 22 22 20 20 20 20 20 20 20 21 21 C O C O C D C O C O C O C O CORE 3 4 5 6 CC 6 CC 1 2 -c* co ro n n 2 3 4 5 6 CC - SECTION 79-81 79-81 7 9 81 7 9 81 79-81 79-81 79-81 79-81 79-31 79-81 79-81 79-81 79-81 79-81 79-81 79-81 7 9 81 79-81 79-81 7 9 81 79-81 79-81 79-81 79-81 79-81 79-81 79-81 7 9 81 79-81 7 9 81 79-81 79-81 C O oo SAMPLE INTERVAL o T e n u ite /la a n g u s tiu m b ih c a ta 7. m m u tis s im a T. cf. T. n k h r o w n i T. p r a e s ta in fo r lh i T. c ie m e n c iae r. sp. 1 T. g e m m a T ru n c o ro ta /o id e s c o t la c tei is T. p s e u d o to p ile n s is 7. aff. T. to p i/e n s is T u rb o r o ta lia c e rro a z u le n s is s.s T. c e rro a z u le n s is co c o a e n s is T. p o m e ro /i 7 p s e u d o a m p lia p e rtu ra 7 . c e rro a z u le n s is c u n ia le n s is T. p a ta g o ru c a T. h o w e n T. cf T. fro n to s a T. cf. T p o ssa g n o e n sis " T u r b o r o ta lia" b e /la " T. " aff. "7 . " b e lia "7. " b irn a g e a e "T . " k u g le ri " 7 " m e n d a c is "7. " e u a p e rtu ra "7. " o p im a nana "T . " p s e u d o k u g le ri "7. " a m p lia p e rtu ra "7. " o p im a o p im a "7. " sp. 1 "7. " p s e u d o m a y e ri T u rb o r o ta h ta r la r k e i 7 cf. 7, p r im itiv e o o o o o o o o ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ • o o o o o ■ ■ ■ ■ ■ ■ ■ o • • ■ • o o • • o • • • • o o o o o o o ■ o o o o o o o o o o o o o • o o • • ■ ■ o • • • • • o o o o o o O o o ■ ■ ■ ■ ■ • • • • o o • • • • ■ o o ■ ■ ■ ■ o • o o o o o o o • o • o o o • • • • o o o ■ ■ o o o • • • o o • • O o 1 G lo b ig e rin a te lla insueta 2 " T u rb o ro ta lia " o p im a o pim a 3 G lo b ig e rin a th e ka se m iin vo lu ta A b undance : O Rare % Few ■ C o m m on 339 E a rly Globrgerinatheka senni MorozoveUa coronata -M . aragonensis G/obigerinatheka curryi - G. euganea 30 30 30 30 30 30 30' 31 31 32 32 32 fSjrsJfSJfSJfSJNjrsJNjrsjrsJfsOfsOfsOrsjfsOfsOfsOfsOfsOfsO t D I D t D C D t D t D C D C O C O C O C O C O C O C O N j s j s j v j s j s j 25 • 25 25 25 25 25 25 26 26 26 26 26 21 3 114-116 C C | o O _ N J o -* O ^ 5 101-103 W N J - 2 3 4 5 6 CC 1 2 3 4 5 6 CC 1 2 3 4 5 6 CC' o ^ - o ^ w ro 1 109111 1 2 3 4 5 6 CC 9 4 96 74-76 5 9 61 95-97 64-66 79-81 79-81 84-86 79-81 79-81 79-81 7 4 76 79-81 89-91 79-81 79-81 79-81 79-81 89-91 5 2 54 24-26 94-96 ' 8 9 91 89-91 7 9 81 79-81 79-81 79-81 7 9 81 7 9 81 7 9 81 79-81 79-81 79-81 • o • o • • • • • • • • • ■ • • • • • o • 0 o o o ■ o o • • ■ • • • o • ■ o o • • • ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 0 o • • o o o o o o o o o o o o o o o o o o o o o • o o o o o o o o o o o o o • o o o o o o o o o • • o o o • o o o o o o • o o o o O o o • o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o * A G E ZONE CORE SECTION SAMPLE INTERVAL T . m inutissim a "T. "sp. 1 Abundance: o Rare • Few ■ Common 3^0

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Creator Fleisher, Robert London (author)

Core Title Early Eocene to early Miocene planktonic foraminiferal biostratigraphy of the western Indian ocean

Degree Doctor of Philosophy

Degree Program Geological Sciences

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Marine Geology,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c29-340974

Unique identifier UC11220321

Identifier DP28533.pdf (filename),usctheses-c29-340974 (legacy record id)

Legacy Identifier DP28533.pdf

Dmrecord 340974

Document Type Dissertation

Rights Fleisher, Robert London

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA