Journal of

Foraminiferal Research

VOLUME 42, NUMBER 4 OCTOBER 2012

Taxonomic reexamination and type-locality assemblage characterization of the late Albian planktonic foraminifera Hed-bergella yezoana Takayanagi and Iwamoto, 1962, from Japan Atsushi Ando ___________________________________________________ 271

Oligocene benthic foraminifera from the Fuente Caldera section (Spain, western Tethys): taxonomy and paleoenviron-mental inferences Raquel Fenero, Ellen Thomas, Laia Alegret and Eustoquio Molina________________________________ 286

Distribution of foraminifera of the Poverty continental margin, New Zealand: implications for sediment transport Stephen J . Culver, Reanna L. Camp, John P. Walsh, Bruce W. Hayward, D. Reide Corbett and C lark R. A lexander _____ .... _________ . ____ . ______________________________________________ ... _ ... ______ . __________________________________________ .______________________________________________ 305

High benthic foraminiferal diversity in polluted Busan North Port (Korea) Jae Ung Choi and Soonmo An ______ ._________ 327

Emendation of Cibicides antarcticlls (Saidova, 1975) based on molecular, morphological and ecological data Magali Schweizer, Samuel S. Bowser, Sergei Korsun and Jan Pawlowski ________________________ . _____ . __ ........ _ .. ____ . __ . __ .________________ 340

Record of deep-sea, benthic elongate-cylindrical foraminifera across the Eocene-Oligocene transition in the North Atlan-tic Ocean (ODP Hole 647 A) Silvia Ortiz and Michael A. Kaminski _______________________________________________ .. ______ . _____ .. __ ._._ .. ___ 345

Foraminiferal fauna and biotopes of a barrier estuary system: St Georges Basin, New South Wales, Australia Lu ke C. Strotz _______________________________________________ . __ . __ ...... __ ._ .. _____________________ . ____ . ________________ . __ ...... _._ ........ _ ............. ____________ ._ 369

Cushman Foundation Membership Directory 20 12 ____ .. _ ...... ___ .. _ .... __________________ . ____ . _______________________ . _____ .. ___ ............ __ . ____ ._ .. _.__ 383

I ndex to Vol ume 42, 20 12 _______________________________________ . __ ._ .. ____ .. _. __________________________________ . ________ .. ___ .. __ ...... _ .. _______ ._ 385

Journal of Foraminiferal Research , v. 42, no. 4, p. 345- 368, October 2012

RECORD OF DEEP-SEA, BENTHIC ELONGATE-CYLINDRICAL FORAMINIFERA ACROSS THE EOCENE-OLIGOCENE TRANSITION IN THE NORTH ATLANTIC OCEAN

(ODP HOLE 647 A)

SILVIA ORTIZ i,2,4 AND MICHAEL A. KAMINSKI2,3

ABSTRACf

The Eocene-Oligocene transition (EOT) at -34 Ma constitutes one of the major episodes of climate change that occurred in the last 50 myr, associated with the establishment of permanent Antarctic ice sheets and the initiation of meridional overturning circulation. We present a high­resolution quantitative study (> 125-J1m fraction) of a group of calcareous, deep-sea, benthic foraminifera with elongate­cylindrical morphologies (Elongate Gp.) across the EOT at high latitudes in the North Atlantic Ocean (ODP Hole 647 A). This group experienced significant declines in abundance and diversity during periods of global cooling, disappearing almost completely during the mid-Pleistocene Climate Transition.

The Elongate Gp .. was a common component of deep-sea benthic foraminiferal assemblages at Hole 647 A (average 20%). The family "Stilostomellidae dominated during the late Eocene and at the EOT; the Nodosariidae slightly dominated during the early Oligocene. During the EOT at Hole 647 A, an abrupt decline in the abundance and diversity of agglutinated foraminifera occurred, but not a distinct taxonomic turnover of the Elongate Gp. Siphonodosaria jacksonensis was the most abundant species and showed the most significant changes in relative abundance across the EOT, from almost no record to a peak of >50% of total benthic foraminifera coincident with the lowest diversity and highest absolute abundance of the Elongate Gp. We attribute these changes to the influence of more than one mechanism, including increased productivity, deepening of the calcite compensation depth, and more vigorous deep­ocean circulation.

INTRODUCTION

The Eocene-Oligocene transition (EaT), -34 Ma, was a pivotal time in Earth's evolution as climate shifted from Early Cenozoic greenhouse to glacial conditions with significant permanent ice sheets on Antarctica. This rapid shift is characterized by an -1.5%0 increase in oxygen­isotope W80) values in benthic foraminifera occurring in two main steps over - 300 kyr (Shackleton and Kennett, 1975; Miller and others, 1987; Zacho.s and others, 2001; Coxall and others, 2005). This isotopic change reflects continental ice accumulation on Antarctica, while estimates of ocean cooling and evidence for Northern Hemisphere glaciation remain controversial (e.g. , Tripati and others,

I Departamento de Estratigrafia y Pa1eontologia. Universidad del Pais Vasco, P.O. Box 644, 48080 Bilbao, Spain

2 Department of Earth Sciences, University College London, Gower Street, London WClE 6BT, U.K.

, Earth Sciences Department, King Fahd University of Petroleum and Minerals, Dhahran, 31261 , Saudi Arabia

4 Correspondence author. E-mail: silvia.ortiz@ehu.es

345

2005; Edgar and ,ethers, 2007; DeConto and others, 2008; Lear and others, 2008). Together with glaciation and global cooling, this climate transition was accompanied by a deepening of the calcite compensation depth (CCD), a sea­level fall, increased ocean alkalinity (Coxall and others, 2005), and an accelerated marine taxonomic turnover (e.g., Prothero and others, 2003). Marine invertebrates under­went one of the largest extinctions in the Cenozoic Period (Raup and Sepkoski, 1986), while phytoplankton was reorganized. The diversity of calcareous nannoplankton decreased, and diatoms became more important as primary producers flourishing in all environments, particularly those with high- and pulsed-nutrient inputs (Katz and others, 2004; Bown, 2005). A major turnover in planktic foraminifera occurred across the Eocene/Oligocene (Eta) boundary, including the extinction of the genera Hantke­nina, Cribohantkenina, and large pseudohastigerinids, which mark the E/O boundary in its type section (Premoli Silva and Jenkins, 1993). Larger foraminifera were also affected, which resulted in the loss of widespread shallow-water carbonate producers such as the Discocyclinidae, Aster­ocyclinidae, and some Nummulitidae (Adams and others, 1986; Pearson and others, 2008; Cotton and Pearson, 2011). Deep-sea benthic foraminifera underwent a mass but gradual extinction from the late Eocene-early Oligocene, with modern type assemblages becoming established (Miller, 1983; Kaminski and others, 1989; Thomas, 1 992a, b, 2007; Thomas and Gooday, 1996; Kaminski and Gradstein, 2005).

Calcareous benthic foraminifera with elongate-cylindri­cal morphologies (Elongate Gp.) reached their greatest relative abundance and diversity levels in the middle Eocene-early Oligocene (e.g., Thomas, 1990, 1992a, b; Thomas and others, 2000; Hayward and others, 201Oa), and progressively declined in abundance during the EaT, the late middle Miocene cooling, and the mid-Pleistocene climate extinction (the " Stilostomella extinction"), when the families Stilostomellidae, Pleurostomellidae, and some of the Nodosariidae died out (e.g., Schonfeld, 1996; Hayward, 2002; Hayward and others, 2010a). These extinctions and taxonomic turnovers have been related to cooling and increase in polar ice volume, possibly because of increased oxygenation of the oceans or increased seasonality in food delivery which originated or intensified during the EaT turnover (e.g., Thomas and Gooday, 1996; Thomas, 2007; Eldrett and others, 2009; Hayward and others, 20 lOa).

Most DSDP and ODP cores spanning the EaT penetrate condensed horizons and cross hiatuses, attributed to increase in ocean-circulation vigor and glacioeustatic sea­level fall associated with Antarctic ice-sheet growth. However, a reasonably continuous EaT is recorded at ODP Hole 647A in the southern Labrador Sea (Srivastava

346 ORTIZ AND KAMINSKI

and others, 1989; Firth and others, 2012), where benthic foraminifera, specifically the Elongate Gp., are common. The taxonomy of this group has usually been chaotic as it mostly relies on distinctive apertural modifications and chamber ornamentation, not always preserved. However, several papers about this group (referred to as the Extinction Gp.) have recently been published, which have greatly shed light on its taxonomy and the global architecture of its population (Hayward, 2001, 2002; Hayward and others, 2005, 2006, 2007, 2009; Kawagata and others, 2005, 2006, 2007; O'Neill and others, 2007; Johnson and others, 2011). Benthic foraminiferal assem­blages through the EOT have usually been analyzed as part of low-resolution long Cenozoic records or with small percentages of calcareous elongate-cylindrical taxa (e.g., Thomas, 1985, I 992b; Molina and others, 2006; Hayward and others, 201Oa). Consequently, there have been no high­resolution records of elongate-cylindrical, deep-sea benthic foraminiferal turnover through the EOT.

In this paper, we document and discuss the quantitative and taxonomic turnover of elongate-cylindrical, deep-sea benthic foraminifera from a high-resolution Eocene-Oligo­cene transition record in the abyssal Hole 647A in the southern Labrador Sea. We aim at shedding light onto the taxonomy of this -'group (Appendix 1) and the nature and timing of the deep-sea changes that took place during the EOT in high north latitudes.

MATERIAL AND METHODS

ODP Site 647, Leg 105, is located in the southern Labrador Sea (western North Atlantic, 53°19.876' N, 46°15.717' W; Fig. lA), and was drilled at a water depth of 3869 m in 1985. Hole 647A penetrated 699 m of sediment, down to the early Eocene, and 37 m of basaltic basement. We selected 55 samples (samples-09 in Fig. IB) from 251.1-351.4 m below seafloor (mbsf) (samples 27R 01W 70-72 to 37R 04W 19-21) and integrated their quantitative study with 27 samples (samples-85 in Fig. lB) studied by Kaminski and others (1989) located between 261.2-352.l mbsf (samples 28R 01W 108-115 to 37R 04W 90- 93). We revised the latter and carried out a new quantitative study integrating both data sets (Appendix 2). All samples are from the middle Eocene-lower Oligocene lithologic Unit mc (24l.l- 530.3 mbsf), pre­dominantly grayish-green nannofossil claystone and clayey nannofossil chalk (Srivastava and others, 1989). Twelve of the newly studied samples and two of the samples from Kaminski and others (1989) with <50 benthic foraminiferal specimens (agglutinated and calcareo,us) were excluded from the quantitative analyses (Appendix 2). Seventeen samples were studied from the EOT in cores 647A-31R and 647A-30R (280.470-29l.540 mbsf), spaced from 15- 84 cm.

We followed a similar metl1odology for sample process­ing as that used by Kaminski and others (1989). After saving sediment for calcareous nannofossil studies, samples were dried at <60°C and then weighed to provide data on absolute abundance. Samples were disaggregated in tap water, or when necessary in a solution of 1 % Calgon, wet­sitwed over a 63-llm sieve, dried, and dry-sieved over a 125-Ilm sieve. To compare our results with those from Kaminski

and others (1989), we picked all the benthic foraminifera from the > 125-J.IID fraction.

In this paper, the calcareous elongate-cylindrical benthic foraminifera (Elongate Gp.) include specimens from the families Stilostomellidae, Nodosariidae, and Pleurostomel­lidae (Table 1; Appendices 1, 2). We present the relative abundance of the Elongate Gp., calculated as a percentage of the total benthic foraminiferal census counts, including agglutinated and ' calcareous taxa; and their absolute abundance, calculated as the number of Elongate Gp. specimens/g of dry bulk sediment (Figs. 2- 5). Species diversity has been analyzed using the Fisher-IX index (Hammer and Harper, 2006; Murray, 2006); dominance, calculated as the relative abundance of the most abundant Elongate Gp. species related to total benthic foraminifera; and species richness, the number of Elongate Gp. species in a sample (Figs. 2-5).

Owing to the site's proximity to continental weathering sources (Labrador and Greenland), the consistently high clay content in the core allowed intervals of pristine carbonate and biosilica microfossils to be preserved, although with very few foraminifera because of clay dilution (Firth and others, 2012). Pearson and Burgess (2008) showed that planktic foraminifera preservation during the middle Eocene and EOT was excellent "glassy." Benthic foraminifera are generally well-preserved empty tests, showing detailed ornamentation and apertural features, which allowed us to carry out the taxonomic study. Some tests show evidence of bioerosion, such as borings, and crystal overgrowths (Figs. 6-10). Elongate taxa commonly show breakage, and to avoid biased results, we considered three small pieces of the same species as one specimen.

All the taxa identified in this study are listed in Appendix 2. Most of them are illustrated in Figures 6-10, and listed with their original references and diagnostic characteristics in Appendix 1. Picked specimen slides are currently housed in the junior author's collection at King Fahd University of Petroleum and Minerals (KFUPM).

PREVIOUS STUDIES-AGE MODEL

Site 647 in the southern Labrador Sea is the only site in the western North Atlantic that recovered a complete Eocene/Oligocene (E/O) boundary interval directly cali­brated to standard chronology by means of a well­constrained age model (Srivastava and others, 1989). This model has recently been enhanced by an integrated study of new data on paleomagnetics, stable isotopes, and biostra­tigraphies of dinoflagellate cysts, calcareous nannofossils, planktic foraminifera, and diatoms (Fig. IB; Firth and others, 2012). Using nannofossil and planktic foraminifera data, Srivastava and others (1989) placed the E/O boundary at ~290.0 mbsf within Core 647A-31R. Kaminski and others (1989; reviewed by Kaminski, 2005) divided the Paleogene sequence at the 647 site into seven assemblages, based on the ranges and relative abundance of character­istic deep-water benthic foraminiferal taxa. The E/O boundary was ' delimited by the last occurrences of 10 agglutinated taxa, such as Reticulophragmium amplectens Grzybowski, and the first common occurrence of Turri/ina

ELONGATE GP ACROSS THE EOT R>: ~ ATI.A.'TflC 347

6'8() OridcxsaJis umbonatus

(Filth and others, 2012)

-2 -1 0 2

Agglutinated

foraminifera

(This study)

B

FIGURE I. A. Paleogeographic location of ODP Site 647 in the North Atlantic during the Eocene-Oligocene Transition (modified from Tucholke and McCoy, 1986). B. Age model for ODP Hole 647A including &180 stable-isotope data from the benthic foraminifer Oridorsalis umbonatus (Firth and others, 2012) and percentage of agglutinated foraminifera (this study). Core recovery, sampling, and benthic foraminiferal biozones of Kaminski and others (1989) on the left. A.: Ammodiscus. D.: Discoaster. G.: Globigerapsis. T.: Turrilina.

alsatica Andreae at 290.32 mbsf within Core 647A-31R, which marks the boundary between the upper Eocene Duquepsammina cubensis-Reticulophragmium amplectens Zone and lowermost Oligocene Ammodiscus latus-Turri/ina alsatica Zone (Fig. lB). The EtO boundary interval in Core 647 A-30R is nearly devoid of deep-water agglutinated foraminifera (Kaminski and others, 1989; this study).

The EtO boundary, located within Chron Cl3r (Gradstein and others, 2004) represented by Core 30R, has been relocated in Hole 647A close to the midpoint of a two-step stable isotopic shift following Pearson and others (2008). The midpoint of this shift occurs at the top of Core 30R or somewhat above within Core 29R (-270-280 mbsf)

(Fig. 1 B). The Oligocene occurs from within Core 29R (- 270-279 mbsf) to the top of Core 15R (-135 mbsf) (Firth and others, 2012).

ELONGATE GP. ABUNDANCE, DIVERSITY, AND COMPOSITION

ELONGATE Gp. VERSUS TOTAL BENTHIC

FORAMINIFERAL ASSEMBLAGES

The Elongate Gp. constitutes - 18.7% of total (calcare­ous + agglutinated) benthic foraminiferal assemblages and 24.4% of calcareous benthic foraminifera in the upper Eocene- lower Oligocene in Hole 647A (Fig. 2). Their

Table I. Genera of calcareous deep-sea benthic foraminifera with elongate-cylindrical morphologies (Elongate Gp.) recorded in ODP Hole 647 A.

Family

Genus

Nodosariidae

Amphimorphinella Chrysalogonium Cribronodosaria Dentalina Glandulonodosaria Grige/is Neugeborina Orthomorphina Plectofrondicularia Proxifrons?

Pleurostomellidae

Ellipsoglandulina Ellipsoidella Ellipsoidina Ellipsopleurostomella Ellipsopolymorphina Nodosarella Pleurostomella

Stilostomellidae

Siphonodosaria Stilostomella Strictocostella

348 ORTIZ AND KAMINSKI

OOP Hole647A

r-r--r-"I" 0

% Elongate Gp _ _ c:::::J

Stilostomellidae Nodosariidae Pleurostomellidae

Species richness

(nO species) FlSher-a H(s) Dominance

. FIGURE 2. Elongate Gp. relative (% of total benthic foraminifera) and absolute (no. Elongate Gp./g dry sediment) abundance, species richness, Flsher-Cl and diversity [H(s)] indexes, and dominance in ODP Hole 647A. Dotted lines indicate no core recovery. (1) benthic foraminiferal biozones of Kaminski and others (1989); (2) magnetic polarity chrons (Firth and others, 2012). EaT: Eocene-Oligocene Transition.

relative abundance strongly fluctuates between 3.4--76.4% (at 308.5 and 282.3 mbsf, respectively), normally ranging between 7-23% (average 18.2%). Absolute abundance values are low, fluctuating between 0.1-9.9 (at 308.47 and 282.32 mbsf, respectively), averaging 2.2 specimens/g of dry bulk sediment. Dominance shows relatively constant values throughout (average 5.7%), but with a distinct spike (53.3%) at the EOT (282.32 mbsf). Not unexpectedly, diversity of the Elongate Gp. related to total benthic foraminifera is low (Fisher-ex index 0.2-7, with an average of 3 between 251.1-308.47 mbsf). However, the species richness of the Elongate Gp. is moderate to high, up to 26 species/sample. .

Rare species show a discontinuous record but most of the species are recorded throughout Hole 647 A. A total of 53 Elongate Gp. species in 20 genera (Table 1; Appendix 2) are identified in the families Stilostomellidae (57.2% abun­dance ), Nodosariidae (32.9%), and Pleurostomellidae (9.9%), with species richness of 11,27, and 15, respectively, for each family. We include below a description of the composition and distribution of these three families, followed by a detailed taxonomy of the Elongate Gp. in Appendix I.

FAMILY STILOSTOMELLIDAE

Eleven species from three genera of the family Stilosto­mellidae are recorded at Hole 647 A (Fig. 3). Eight species belong to the genera Siphonodosaria, while only two belong to Strictocostella and one to Stilostomella. Siphonodosaria jacksonensis is the most abundant followed by Stricto costella japonica, Siphonodosaria subspinosa, and Strictocostella cf. S. matanza. The Stilostomellidae increased in relative abun­dance and diversity within the EOT, reaching 65% of total benthic foraminifera at 282.32 mbsf. All species were recorded throughout Hole 647A except Stilostomella rugosa, which was found only in the uppermost samples (lower Oligocene).

FAMILY NODOSARIIDAE

This family is the most diverse, with 27 species in ten genera (Table 1; Fig. 4). Chrysalogonium is the most diverse genus with seven species, followed by Cribronodosaria (six) and Dentalina (four). Cribronodosaria stimulea and Neugeborina longiscata are the most abundant nodosariid species in Hole 647A, with comparatively constant relative abundance values.

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 349

III

13 I/)

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~ :& :& (tJ ~(tJ 2 OOP ~~

(tJ ~ ~(tJ I/) III .g~ .§ ~ I/) 1/)1'.1 .g .g~ ::::: Ul

Hole 647A 0(1) '0(1) ~

:.::: 8~ 01:: (I)

"iii 1::1:: g .Q"l ::J g-l:! g~ O.S: E 2: % Family 00 0:; ~ I:: 0'- 0::J §~ .s

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..... :;::; richness -C/).~ C/)Q. cr.i C/).~ C/)C/) C/)~ C/)I/) CI)

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FIGURE 3. Stratigraphic record of the relative abundance of the family Stilostomellidae and its more common species (% of total benthic foraminifera) in ODP Hole 647 A. Dotted lines correspond to no recovery of cores. (I) benthic foraminiferal biozones of Kaminski and others (1989); (2) magnetic polarity chrons (Firth and others, 2012). EOT: Eocene-Oligocene Transition.

Chrysalogonium polystomum is the most abundant nodosariid within the EOT.

The Nodosariidae are a common component of the Elongate Gp. throughout the hole and increased in relative abundance and diversity from the EOT upward, making up more than 25% of the total assemblage in the uppermost sample at 251.10 mbsf (Fig. 4).

The most abundant species occur throughout the hole, while rarer species show a discontinuous record, mostly within the upper Eocene. Distinctively, Proxifrons? flabell­liformis is only recorded in the EOT, coincident with the highest species richness of the family . .

F AMIL Y PLEUROSTOMELLIDAE

This family is the least abundant (usually <3%) in Hole 647A, but is relatively diverse with 15 species in seven genera (Table 1; Fig. 5). Pleurostomella is the most diverse genus (8 species) with Pleurostomella obtusa and P. acuta the most abundant pleurostomellids. The relative abundance and diver­sity of this family slightly increased in the upper part of the EOT and the lower Oligocene. Ellipsoidella pleurostomelloides was the

only species of the Elongate Gp. that apparently (due to its low abundance) disappeared from the site below the EOT. Pleurostomella velascoensis shows its FO in the upper part of the EOT at 284.97 mbsf.

FAUNAL TURNOVER

AGE INTERVALS

On the basis of the absolute and relative abundance of the Elongate Gp, its species richness and diversity, and the age model for Hole 647A (Kaminski and others, 1989; Firth and others, 2012), we differentiated three age intervals: late Eocene (divided into Subintervals la and Ib), the EOT (divided into Subintervals 2a and 2b) and early Oligocene (Figs. 2-5).

INTERVAL I-LATE EOCENE

Subinterval 1 a

The Elongate Gp. (average 15%) was a common component of total benthic foraminiferal assemblages, \vith low absolute abundance throughout this subinterval but

350 ORTIZ AND KAMINSKI

OOP Hole 647A <0

~ % Family :§ Nodosariidae ~

.~ <0 C/J .g 0<0 t:::Q) e-s :g .§ Otj

r

r

Species richness

FIGURE 4. Stratigraphic record of the relative abundance of the family Nodosariidae and its more common species (% of total benthic foraminifera) in ODP Hole 647A. Dotted lines indicate no core recovery. (I) benthic foraminiferal biozones of Kaminski and others (1989); (2) magnetic polarity chrons (Firth and others, 2012). EOT: Eocene-Oligocene Transition.

increasing diversity in the upper part. The families Stilostomelliidae and Nodosariidae equally dominated the Elongate Gp. (85%), while the family Pleurostomelli­dae constituted 15% (Fig. 2). Siphonodosaria jaeksonensis and Cribronodosaria cf. C. stimulea were the most abundant species (Figs. 3, 4). The FOs of several species are recorded in this subinterval, but seem to be an artifact of the sampling due to their rareness. The LO of Ellipsoidella pleurostomelloides was recorded at the top of this subinterval (Fig. 5).

Subinterval 1 b

This subinterval is characterized by the lowest relative (average 12%) and absolute abundance values and poorest core recovery in Hole 647A (Fig. 2). The diversity and relative abundance of the Elongate Gp. declined moderately compared to assemblages from Subinterval la. The Elongate Gp. composition was similar to the latter subinterval, but the Pleurostomelliidae were scarcer (7%). Rare species showed a very discontinuous record. An increase in the relative abundance of Strietoeostellajaponiea characterized the upper part of this subinterval (Fig. 3).

I NTERVAL 2-EoCENE-OUGOCENE TRANSITION (EOT)

EOT

This interval corresponds to the EOT. Its base coincides with the LO of the calcareous nannofossil D. saipanensis Bramlette and Riedel (Firth and others, 2012) and the base of the A. latus-T alsatiea benthic foraminiferal zone used to locate the E/O boundary (290.32 mbsf) by Kaminski and others (1989). Moreover, the EOT had a strong decline in the relative abundance of agglutinated benthic foraminifera (Fig. 1 B). Distinct changes in the relative abundance of some of the common Elongate Gp. species and their highest relative and absolute abundance characterize the EOT, and allow its division into Subintervals 2a and 2b.

Subinterval2a

This subinterval is characterized by a marked increase in the relative abundance of the Elongate Gp., which remained high (> 17%) throughout (Fig. 2). Absolute abundance of the group also increased markedly, showing two peaks at 286.4 and 289.2 mbsf. Diversity gradually increased to high values, only to decrease in the uppermost

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 351

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FIGURE 5. Stratigraphic record of the relative abundance of the family Pleurostomelliidae and its more common species (% of total benthic foraminifera) in ODP Hole 647A. Dotted lines indicate no core recovery. (I) benthic foraminiferal biozones of Kaminski and others (1989); (2) magnetic polarity chrons (Firth and others, 20q). EaT: Eocene-Oligocene Transition.

part of the subinterval. The Stilostomellidae (62%) strongly dominated the Elongate Gp., and its species experienced major changes in relative abundance (Figs. 2, 3). Stricto­costella cf. S. matanza, Siphonodosaria subspinosa, and S. lepidula showed an abrupt and marked increase in relative abundance. Strictocostella japonica was also abundant with percentages similar to Subinterval 1 b. Siphonodosaria jacksonensis, the most abundant species through the upper Eocene, peaked at the base of this subinterval coinciding

with a peak in absolute abundance of the Elongate Gp. (289.2 mbsf), but it declined strongly to almost no record in the upper part of the interval (Fig. 3). The Nodosariidae, slightly more abundant (30% of Elongate Gp.) than in Interval 1, increased in species richness (Fig. 4) to the highest values in Hole 647A (up to 18 species/sample). Chrysalogonium polystomum increased distinctively in relative abundance, being the most abundant nodosariid in this subinterval that was also characterized by the only

ORTIZ A 0 KAM I SKI

FIGURE 6. Scanning electron micrographs of the apertures of elongate-cylindrical deep-sea benthic foraminiferal genera in ODP Hole 647A. 1 Chrysalogonium. 2 Cribronodosaria. 3 Species A, gen. and sp. indet. 4 Orthomorphina. 5 Glandulonodosaria. 6 Dentalina. 7 Prox ifrons? 8 Stilostomella. 9 Siphonodosaria. 10 StriclOcostella. 11 Ellipsoidella . 12 PleuroslOmella. Scale bars = 25 ~m .

occurrence of the nodosariid Proxifrons? flabellliformis and the FO of Pleurostomella velascoensis (Figs. 4, 5).

Subinterval2b

The boundary between Subintervals 2a and 2b at 284.5 mbsf is marked by a decrease in absolute abundance of the Elongate Gp. to values akin to Interval I, with the exception of one pivotal sample at 282.3 mbsf (Fig. 2). This sample had the highest absolute and relative abundance (76%) of Elongate Gp. specimens in Hole 647A and the highest dominance (Figs. 2, 3) of Siphonodosaria jackso­nensis (53.3% of total benthic foraminifera). This species was the most abundant in the subinterval (Figs. 3, 4), followed by S. subspinosa, S. japonica, and S. annulifera (Stilostomellidae), and C. polystomum (Nodosariidae). Strictocostella cf. S. matanza, common in Subinterval 2a, is not recorded here. The Pleurostomellidae were less abundant in this subinterval but increased in relative abundance and more distinctively in diversity, reaching

values similar to those in Subinterval la (Figs. 2, 5). Pleurostomella velascoensis first occurred at the base of this subinterval. The diversity of the Elongate Gp. continued to decrease from its peak at the top of Subinterval 2a, giving a symmetrical pattern to the EOT occurrences (Fig. 2).

INTERVAL 3- EARLY OLIGOCENE

This interval corresponds to the early Oligocene, included in magnetochron CI3n (Firth and others, 2012). The Elongate Gp. constituted 22% of the total assemblage, slightly lower than its average in the EOT of Interval 2 but higher than in late Eocene Interval I (Fig. 2). The diversity of the Elongate Gp. fluctuated, but overall had the highest values in Hole 647A. The absolute abundance values were lower than in Interval 2 but higher than in Interval I. The Nodosariidae (50.4%) dominated the Stilostomellidae (31 %) and Pleurostomellidae (18.6%) in this interval The latter family had its highest relative abundance values in the hole, slightly higher than in Subinterval 2b. Siphonodosaria

ELO GATE GP ACROS THE EOT IN ATLA TIC 353

FIGURE 7. Scanning electron micrographs of the family Nodosariidae in ODP Hole 647 A. 1,2 Amphimorphinella amchilkaensis, mbsf _61. _ -.9-t. 3,4 Chrysalogonium gomphiformis, mbsf 285.94,261.18.5-7 Chrysalogonium cf. C. chapmani, mbsf 285 .94. 8,9 Chrysalogoniwn PolyslOmlD1l. mbs[ 262.65, 281.68. 10 Chrysalogonium aff. C. polystomum, mbsf 328.90. 11 Chrysalogonium setosum, mbsf 285.94. 12, 13 Chrysalogoniwn p .. -\ .. m -285.50, 328.90. 14,15 Cribronodosaria equisetiformis, mbsf 328.90.16,17 Cribronodosaria sp. A, mbsf284.97, 291.54. 18, 19 Cribronodosaria srimulea_ mbsf262.65, 300.30. 20 Species A, gen. and sp. indet, mbsf264.12. 21 Dentalina sp. A, mbsf262.65. Scale bars = 100 J.Im.

354 ORTIZ AND KAMI SKI

FIGURE 8. Scanning electron micrographs of the families Nodosariidae (1-4) and Stilostomellidae (5- 19) in ODP Hole 647 A. 1 Glandulonodosaria ambigua, mbsf 349.89. 2 Glandulonodosaria trincherasensis, mbsf 264.12. 3 Orlhomorphina jedlitschkai, mbsf 290.84. 4 Orthomorphina cf. 0. jedlitschkai, mbsf 265.5 1. 5 Stilostomella rugosa, mbsf 261.55. 6, 7 Neugeborina cf. N. longiscata, mbsf 283.50. 8, 9 Neugeborina longiscata, mbsf 265.51 , 310.62. 10 Siphonodosaria? sp. A, mbsf 286.42. 11 , 12 Proxifrons? j1abellliformis, mbsf 285 .94. 13-16 Siphonodosariajacksonensis, mbsf 28 1.68, 282.32, 331.91 , 282.32. 17-19 Siphonodosaria pomuligera, mbsf 282.32, 289.24, 282.32. Scale bars = 100 fllT1.

ELONGATE GP ACROSS THE EOT IN ATLANTIC 355

FIGURE 9. Scanning electron micrographs of the fami ly Stilostomellidae in ODP Hole 647A. 1,2 Siphonodosaria annuli/era, mbsf 261.00.2 1.1-. 3, 4 Siphonodosaria gracillima, mbsf 332.30, 310.80. 5, 6 Siphonodosaria lepidlila. mbsf 286.42, 285.50. 7 Siphonodosaria longispina. mb f _ -. . . 9 Siphonodosaria subspinosa, mbsf 281.68, 281.15. 10-12 Srrictocostella cf. S. maran=a. rnbsf 286.42, 261.55, 262.65. 13, 14 Strictocostella sp. jU\enile. mbsf 285.94. 15-18 Strictocostella japonica, mbsf 285.35, 262.65, 261.00, 288. 3. Scale bars = I 00 ~m.

356 ORTIZ A 0 KAMI SKI

FIGURE 10. Scanning electron micrographs of the family Pleurostomellidae in ODP Hole 647A. I Ellipsoidella pleuroslOmelloides, mbsf 332.30. 2 Pleuros/omella velascoellsis, mbsf 261.00. 3 PleuroslOmella acuta, mbsf 26 1.55. 4 Pleurostomella parviapertura, mbsf 287.61 . 5 Pleuros/omella sp. A, mbsf 328.90. 6 Pleurostomella brevis, mbsf 328.90. 7 Pleurostomella allema/ls, mbsf 285.35. 8, 9 Pleuros/omella obtusa, mbsf 285.35, 329.31. 10 Nodosarella sp. A, mbsf 288.73. Scale bars = 100 !1m.

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 357

jacksonensis and C. stimulea were the most abundant species, whereas S. cf. S. matanza, Chrysalogonium poly­stomum, Pleurostomella obtusa, and Neugeborina longiscata were common. The FO of Stilostomella rugosa occurred in this interval, the only species of this genus recorded in this study.

DISCUSSION

GLOBAL RECORD OF THE ELONGATE Gp. DURING THE LATE EOCENE- EARLY OLIGOCENE

The Elongate Gp. (average 20%) was a common component of abyssal foraminiferal assemblages within the late Eocene-early Oligocene interval in Hole 647A. The Stilostomellidae dominated the Elongate Gp. in the late Eocene and at the EOT. In the early Oligocene, the Stilostomellidae had the same abundance as in the late Eocene, but the Nodosariidae increased in relative abun­dance and dominated the Elongate Gp. Previous studies from the North Atlantic (e.g., Site 548 in Hayward and others, 201Oa) show that the maximum relative abundance of the Elongate Gp. was low « 15%) throughout the Paleocene and most of the Eocene, increasing from the late Eocene to an earliist Miocene peak (50%) before declining gradually through the Neogene with a rapid Pleistocene collapse. The Stilostomellidae were the largest component of the Elongate Gp. in the North Atlantic and also globally at lower bathyal-abyssal depths (Hayward and others, 20 lOa). The Pleurostomellidae and Nodosariidae were less abundant and showed similar relative abundance patterns during the late Eocene- early Oligocene in the North Atlantic, but not globally (Hayward and others, 2010a). The Pleurostomellidae were more abundant at abyssal depths, while the Nodosariidae were more common at shallower depths (Katz and others, 2003; Thomas, 2007; Hayward and others, 20 lOa, 201Ob; Johnson and others, 2011). Site 548 is located on the continental slope of the northeast Atlantic, presently at lower bathyal depths, with average relative abundances of 10% for the Pleurostomelli­dae and Nodosariidae during the late Eocene and early Oligocene. Within the deeper abyssal depths of Hole 647 A, however, the Pleurostomellidae were a minor component of the Elongate Gp. (10%), with low relative abundances (average < 2%).

The record of the Elongate Gp. in North Atlantic abyssal­water depths during the EOT in Hole 647A shows that there was no significant change in faunal composition, but in abundance and diversity. Hayward and others (2010a) stated that there was no concurrent rapid change in the Extinction Gp. during the EOT, but after the rapid cooling there was an elevated level of species turnover globally in the early Oligocene. As already stated, the taxonomic turnover in Hole 647A is minor, although there are some similarities with other North Atlantic sites. Hayward and others (20 lOa) recorded at Site 548 the LO of three species and the FO of five species, including Stilostomella rugosa whose FO is also recorded in the lowermost Oligocene in Hole 647A (Fig. 3; Appendix 2). Additionally, the average relative abundance of- the Extinction Gp. peaked in the uppermost Eocene followed by a decline in the lower Oligocene (fig. 18 in

Hayward and others, 201Oa), similar to our study, although the lower resolution of their data must be kept in mind. During the EOT, the Elongate Gp. and, in particular, the Stilostomellidae reached the highest relative abundance (up to 76% of the total assemblage at 282.32 mbsf) in Hole 647 A. Noticeably, these values are similar to those in the Southern Ocean (up to 70%; Thomas, 1990,2007; Thomas and others, 2000), supporting the hypothesis that the Stilostomellidae were more abundant at high latitudes, especially in the late Eocene (Thomas, 2007). This family increased in relative abundance during the EOT, but their species show different abundance patterns in Hole 647 A. The most abundant species, Siphonodosaria jacksonensis, is present in the lowermost part of Subinterval 2a (basal EOT) but essentially absent in the remainder of that interval in favor of other stilostomellid species that sharply increased in relative abundance. However, during Subinterval 2b (upper EOT) S. jacksonensis returned, making up to 53% of total benthic foraminifera. Due to misidentification of the species in the literature (see Appendix I) it is difficult to track the distribution of S. jackson ens is in other oceans during the EOT.

INSIGHTS INTO THE EOCENE-OLIGOCENE CLIMATE TRANSITION

The Eocene-Oligocene transition (EOT) was a period of global climatic and oceanographic change, associated with increased extinction and ecological reorganization on land, at the ocean surface, and in shallow seas to the deep ocean (for a review, see Coxall and Pearson, 2007). During the EOT, ice growth followed an extended period of global cooling (Zachos and others, 2001; Coxall and others, 2005; Katz and others, 2008, 2011; Eldrett and others, 2009). Some extinctions and faunal changes have been related to the sea-surface cooling and later sea-level fall, associated with the maximum glacial conditions of the early Oligocene (Coxall and Pearson, 2007; Wade and Pearson, 2008; Cotton and Pearson, 2011). Deep-sea benthic foraminifera underwent a gradual but severe extinction from the middle­late Eocene, culminating in the EOT (Prothero and others, 2003). However, little change is associated with the EOT itself (Thomas, 1992a, b; Coccioni and Galeotti, 2003; Molina and others, 2006). A decrease in abundance of the Elongate Gp. during the EOT and the middle Miocene and its almost complete extinction during the middle Pleistocene are thought to reflect the impact of global cooling (Thomas, 2007; Hayward and others, 20 lOa). Our data from high northern latitudes, however, indicate that the diversity and relative and absolute abundance of the Elongate Gp. increased during the EOT (Fig. 2). Considering the age model for Hole 647A (Srivastava and others, 1989; Firth and others, 2012), the peak in Elongate Gp. during the EOT corresponds to the precursor cooling before the peak DI80 values (Oi-I) or Early Glacial Maximum (Miller and others, 2008). The high surface-to-volume ratio of the Elongate Gp. species is indicative of an infaunal habitat tolerant of high organic-carbon flux and/or lower oxygen conditions (e.g., Corliss and Chen, 1988; Thomas and others, 2000; Kawagata and others, 2005). The diversity of the assemblages and the lack of sedimentological features indicative of low

358 ORTIZ AND KAMINSKI

oxygen conditions (Srivastava and others, 1989) point to well­oxygenated bottom waters during the EOT at Hole 647A. Additionally, the increased absolute abundance of the Elongate Gp. during the EOT supports the hypothesis of increased productivity. Based on benthic foraminifera, Diester-Haass and Zahn (1996, 2001) and Diester-Haass and Zachos (2003) recorded a sudden global increase in productivity that was associated with the more vigorous overturning of the earliest Oligocene ocean. Other biotic groups (e.g., planktic foraminifera, radiolarians, calcareous nannoplankton) also pointed to increased productivity at that time, not only in Hole 647 A (Lazarus and Pallant, 1989) but in the Southern Ocean and mid-and low-latitude regions (for references, see Coxall and Pearson, 2007).

An increase in dominance is typical of stressed environ­ments and periods of disturbance (Urbanek, 1993). The distribution of Siphonodosaria jacksonensis during the EOT seems to reflect a period of ecological disturbance, with a major disruption in the upper part of the EOT (Subinterval 2b). However, diversity values are moderate to high during the EOT, suggesting mUltiple environmental factors influ­encing the deep-sea community.

The EOT was a time of significant faunal turnover among agglutinated benthic foraminifera at Hole 647A (Fig. IB; KaminslCi and others, 1989; Kaminski, 2005; this study). This turnover may reflect a drop in the CCD (van Andel, 1975; Coxall and others, 2005). It is possible that in carbonate-rich environments the calcareous benthics might outcompete the agglutinates, but to what extent the reduction of habitat space beneath the CCD causes extinction of deep-water agglutinated-foraminifera species still remains unclear (Kaminski and Gradstein, 2005). The abrupt «300 kyr) and large-scale (> 1 km) drop in the CCD is thought to reflect better ventilation of the deep ocean associated with climatic cooling and the onset of Antarctic glaciation. However, the relationship between these events is poorly understood. The increase in abundance of the Elongate Gp. and the depletion and extinction of agglutinated foraminifera (Kaminski and others, 1989; Kaminski, 2005) were coeval in Hole 647A. Hence, it seems reasonable to link the changes in the Elongate Gp., including the inferred higher productivity, to the CCD drop andlor associated changes, such as more vigorous ocean circulation and, ultimately, to global cooling. Giving that the EIO boundary is located just above the EOT interval in Hole 647A, i.e., below the prominent oxygen isotope excursion (Oi-1) (following Pearson and others, 2008), our study shows that these changes preceded the Glacial Maximum.

ACKNOWLEDGMENTS

We thank associate editor B. Hayward and the reviewers L. Alegret and A. Bhaumik for their insightful comments that improved the manuscript. This research was funded by the Natural Environmental Research Council of the United Kingdom (Grant NE/G01601111) . Silvia Ortiz acknowledg­es the Spanish Ministery of Science and Innovation for a Juan de la Cierva research contract and funding (CGL 2008-00009/BTE, CGL 2011-23077, CGL-2011-23770).

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APPENDIX I

Received 27 February 2012 Accepted 2 August 2012

This appendix describes the taxonomic features and synonymies of elongate-cylindrical, deep-sea benthic foraminifera (Elongate Gp.) at ODP Hole 647A. We have largely followed the taxonomic work of Hayward (2002) and following papers by Hayward and coauthors (see references). Although these studies are mostly from the late Pliocene­middle Pleistocene, the peaks of species durations (length of time between the first and last stratigraphic occurrences of a species) in the

North Atlantic were in the 50--59 and 20--29 Myr categories (Hayward and others, 2010a).

Family NODOSARIIDAE Ehrenberg, 1838

Remarks. We have included specimens with cribrate apertures in Amphimorphinella, Chrysalogonium, and Cribronodosaria. Those in the latter genus show an aperture in a domelike trematophore with a reticular mesh of small pores. The diameter of the aperture is usually smaller (related to the cross-section surface of the last chamber) than in Chrysalogonium specimens, which show an irregular mesh of pores. Amphimorphinella is initially biserial.

Genus Amphimorphinella Keyzer, 1953 Type species: Nodosaria polystoma Schwager, 1866

Remarks. Amphimorphinella includes specimens compressed in the early stage, with a cribrate aperture and an initial but inconsistent biserial portion.

Amphimorphinella amchitkaensis (Todd, 1953) Figs. 7.1, 7.2

Dentalina? amchitkaensis Todd, 1953, p. 3, pI. I, figs. 12-19.

Remarks. This species is distinguished by its initial biserial portion (when present), longitudinal costae ornamentation, and early com­pressed-globular chambers separated by depressed sutures.

Genus Chrysalogonium Schubert, 1908 Type species: Nodosaria polystoma Schwager, 1866

Remarks. As used here, Chrysalogonium includes specimens with a cribrate aperture, independent of the chamber ornamentation. Some well-preserved specimens allowed us to see the details of the complex aperture (Fig. 6.1), which is formed by several tooth-like projections distributed evenly along the perimeter of the aperture, joining at the center in the shape of a polygon.

Chrysalogonium cf. C. chapmani (Tappan, 1940) Figs. 7.5-7.7

Nodosaria chapmani Tappan, 1940, p. 103, pI. 16, figs. 9, 10.

Remarks. Specimens are characterized by weak longitudinal costae and cylindrical chambers, increasing rapidly in height as added. Our specimens differ from the holotype in having a rounded apex rather than a pointed one, and from C. polystomum in the costae ornamentation. Well-preserved specimens show short prolocular spines.

Chrysalogonium gomphiformis (Schwager, 1866) Figs. 7.3, 7.4

Nodosaria gomphiformis Schwager, 1866, p. 220, pI. 5, fig. 48. Chrysalogonium aff. C. gomphiformis (Schwager). Hayward, 2002,

p. 297, pI. 2, figs. 15, 16.

Remarks. This species differs from others in Chrysalogonium in having the top of the last chamber smooth.

Chrysalogonium polystomum (Schwager, 1866) Figs. 7.8, 7.9

Nodosaria polystoma Schwager, 1866, p. 217, pI. 5, fig. 39; Srinivasan and Sharma, 1980, p. 29, pI. 5, figs. 22, 23 (neotype).

Chrysalogonium polystomum (Schawager). Kawagata and others, 2006, p. 237, pI. I, figs. 3a, b.

Remarks. This species is distinguished by its subpyriform chambers and constricted sutures. When the last chamber or apertural features are not preserved, it is difficult to distinguish from Cribrono­dosaria stimulea.

Chrysalogonium aff. C. polystomum (Schwager, 1866) Fig. 7.10

Nodosaria polystoma Schwager, 1866, p. 217, pI. 5, fig. 39; Srinivasan and Sharma, 1980, p. 29, pI. 5, figs. 22, 23 (neotype).

362 ORTIZ AND KAMINSKI

_ Remarks. These specimens differ from C. polystomum in the less elongate chambers and spines at the base of the chambers.

Chrysalogonium setosum (Schwager, 1866) Fig. 7.11

Nodosaria setosa Schwager, 1866, p. 218, pI. 5, fig. 40. Chrysalogonium setosum (Schwager). Hayward, 2002, p. 297, pI. 2, figs.

21-24.

Remarks. This species is distinguished by its globular chambers ornamented with short spines.

Chrysalogonium sp. A Figs. 7.12, 7.13

Remarks. These specimens are characterized by elongate chambers ornamented with distinct, longitudinal costae, usually divided into spines, intercalated with lines of shorter spines.

Genus Cribronodosaria Le Calvez, de Klasz, and Brun, 1974 Type species: Cribronodosaria africana Le Calvez, de Klasz, and Brun, 1974

Remarks. Loeblich and Tappan (1987) included in Cribronodo­saria specimens with an aperture of numerous angular pores forming a reticular mesh in a domelike trematophore, and with smooth surfaces or with a few pustules or spines in the median region of the chambers. However, we consider apertural features more determi­nant than chamber ornamentation in accordance with Hayward (2002).

Cribronodosaria equisetiformis (Schwager, 1866) Figs. 7.14, 7.15

Nodosaria equisetiformis Schwager, 1866, p. 212, pI. 5, fig. 30. Chrysalogonium equisetiformis (Schwager). Srinivasan and Sharma,

1980, p. 28, pI. 5, figs. 18, 19; Boersma, 1986, pI. 9, figs. 1-3; Hayward 2002, p. 297, pI. 2, figs. 13, 14.

Remarks. This species is characterized by numerous weak longitu­dinal costae which twist along the elongate test.

Cribronodosaria stimulea (Schwager, 1866) Figs. 7.18, 7.19

Nodosaria stimulea Schwager, 1866, p. 226, pI. 6, fig. 57. Dentalina stimulea (Schwager). Hayward, 2002, p. 298, pI. 2, figs. 34,

35.

Remarks. This common species is characterized by rectilinear to slightly curved elongate tests, with elongate chambers separated by constricted, horizontal sutures. Surface smooth. Rounded apex with a thick spine if preserved.

Cribronodosaria sp. A Figs. 7.16, 7.17

Remarks. These specimens are similar to C. equisetiformis but differ in possessing fewer costae, which are more distinct and stronger and do not extend over the last chamber; test also is larger with fewer chambers.

Species A, gen. and sp. indet. Fig. 7.20

Remarks. These specimens show a very distinct cribrate aperture, plate-like with a row of pores at the base, which cannot be included in Chrysalogonium or Cribronodosaria. When the last chamber is broken off, it is difficult to distinguish from C. stimulea.

Genus Dentalina Risso, 1826 Type species: Nodosaria (les Dentalines) cuvieri d'Orbigny, 1826

Remarks. We have included in Dentalina specimens with an elongate and arcuate test and a terminal, radial aperture.

Dentalina sp. A Fig. 7.21

Remarks. Slender elongate specimens with the last chamber slightly inflated.

Genus Glandulonodosaria Silvestri, 1900 Type species: Nodosaria ambigua Neugeboren, 1856

Remarks. Loeblich and Tappan (1987) considered Glandulonodo­saria as a junior synonym of Nodosaria . However, the aperture of the Glandulonodosaria type species is a simple circular orifice unlike the aperture of Nodosaria. We include in Glandulonodosaria species with slightly overlapping, inflated and globular chambers. The genus differs from Orthomorphina in lacking an everted apertural rim.

Giandulonodosaria ambigua (Neugeboren, 1856) Fig. 8.1

Nodosaria ambigua Neugeboren, 1856, p. 71, pI. 1, figs. 13-16. Orthomorphina ambigua (Neugeboren). Hayward, 2002, p. 299, pI. 2,

figs. 44, 45.

Remarks. Hayward (2002) included specimens with squashed spherical chambers of similar size throughout and smooth to weakly pustular ornamentation. We agree with these key features and place distinctly pustular specimens in Glandulonodosaria trincherasensis.

Glandulonodosaria trincherasensis (Bermudez, 1949) Fig. 8.2

Nodogenerina trincherasensis Bermudez, 1949, p. 179, pI. 11, fig. 60. Orthomorphina trincherasensis (Bermudez). Hayward, 2002, p. 300,

pI. 2, figs. 53, 54; Hayward and Kawagata, 2005, pI. I , figs. 22, 23.

Remarks. This species differs from G. ambigua in its stronger pustular ornamentation and slightly more elongate chambers.

Genus Neugeborina Popescu, 1998 Type species: Nodosaria longiscata d'Orbigny, 1846

Remarks. This genus differs from other nodosariids in its long cylindrical chambers and characteristic sutures, slightly inflated (like a bamboo stem) to slightly depressed (Popescu, 1998). Surface smooth or ornamented with longitudinal or helicoidal fine rugosities.

Neugeborina longiscata (d'Orbigny, 1846) Figs. 8.8, 8.9

Nodosaria longiscata d'Orbigny, 1846, p . 32, pI. I, figs. 10-12; Papp and Schmid, 1985, p. 23, pI. 3, figs. 1-5; Hayward, 2002, pI. 2, fig. 43.

Nodosaria? iongiscata d'Orbigny. Bolli and others, 1994, p. 102, pI. 26, figs. 35, 36.

Remarks. The species is distinguished by very long and slender cylindrical chambers. Proloculus ovate, inflated. Siphonodosaria? sp. A is very similar to N. iongiscata but differs in the apertural bifid tooth of the former. Incomplete specimens are very difficult to distinguish from Siphonodosaria? sp. A.

Neugeborina cf. N. iongiscata (d'Orbigny, 1846) Figs. 8.6, 8.7

Nodosaria longiscata d'Orbigny, 1846, p. 32, pI. 1, figs. 10-12.

Remarks. Specimens of this species, always found in fragments, differ from N. longiscata in having bigger and thicker chambers, and a surface ornamented with fine longitudinal or helicoidal striae.

Genus Orthomorphina Stainforth, 1952 Type species: Nodogenerina havanensis Cushman and

Bermudez, 1937

Remarks. We have followed Hayward (2002) by including Ortho­morphina in the family Nodosariidae instead of the Stilostomellidae (Loeblich and Tappan, 1987), because it lacks an apertural tooth.

Orthomorphina jedlitschkai (Thalmann, 1937) Fig. 8.3

Nodogenerina jedlitschkai Thalmann, 1937, p. 341. Orthomorphina jedlitschkai (Thalmann). Hayward, 2002, p. 299, pI. 2,

figs . 48, 49; Hayward and Kawagata, 2005, pI. 1, figs. 12, 13.

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 363

- Remarks. This species is characterized by globular chambers, with later chambers tending to become elongate and smaller. The widest part of the test is halfway instead of at the aperture.

Orthomorphina cf. 0. jedlitschkai (Thalmann, 1937) Fig. 8.4

Nodogenerina jedlitschkai Thalmann, 1937, p. 34l.

Remarks. These specimens differ from 0. jedlitschkai in having a larger and thicker test.

Genus Proxifrons Vella, 1963 Type species: Frondicularia advena Cushman, 1923

Remarks. We recorded one species, Proxifrons? flabellliformis, with features of the subfamily Plectofrondiculariinae. It has a terminal aperture with a denticulate elevated rim, the denticles tending to meet centrally to produce a multiple aperture as in Plectofrondicularia. However, the latter genus possesses a peripheral keel or truncate margins not seen in our material. We tentatively include our specimens in Proxifrons because of the chevron-like chambers, although they are not strongly overlapping at the margins.

Proxifrons? flabelliformis (Guppy, 1894) Figs. 8.11, 8.12

Frondiculariaflabelliformis Guppy, 1894, p . 651 , pI. 41, fig . 5.

Description. Test elongate, lanceolate, greatest thickness at the center of the test, thinning towards the periphery, and twisted over its longitudinal axis; initial end rounded. Chambers initially biserial, later uniserial, rectilinear, broad and low, arched centrally to slightly chevron shaped, projecting downward or even spinose; the last chambers somewhat inflated. Sutures distinct, more depressed as added, occasionally crenulated. Wall calcareous, finely perforate; surface smooth. Aperture terminal, with denticulate elevated rim, the denticles tending to meet centrally to produce a multiple aperture.

Family STILOSTOMELLIDAE Finlay, 1947 Genus Siphonodosaria Silvestri, 1924

Type species: Nodosaria abyssorum Brady, 1881

Remarks. Aperture is rounded, produced on a slender neck with a very distinct flange halfway up the neck, a phialine lip at the top of the neck, a distinct bifid tooth from a fold in the wall of the neck, projecting into the aperture, and numerous, short, internal denticles around the perimeter of the aperture. The flange is divided into longitudinal spines overhanging the neck, which has an external groove reflecting the position of the inner tooth. Chambers are less overlapping as added.

Siphonodosaria annulifera (Cushman and Bermudez, 1937) Figs. 9.1, 9.2

Ellipsonodosaria annulifera Cushman and Bermudez, 1937, p. 28, pI. 5, figs. 8, 9.

Stilostomella annulifera (Cushman and Bermudez). Beckmann, 1954, p. 370, pI. 21, fig. 23.

Siphonodosaria annulifera (Cushman and Bermudez). Ortiz and Thomas, 2006, p. 132, pI. 11, fig. 6.

Remarks. This species is characterized by elongate, slightly inflated chambers, separated by broad transparent sutures.

Siphonodosaria gracillima (Cushman and Jarvis, 1934) Figs. 9.3, 9.4

Ellipsonodosaria nuttalli var. gracil/ima Cushman and Jarvis, 1934, p. 72, pI. 10, fig. 7.

Siphonodosaria gracillima (Cushman and Jarvis). Kawagata and others, 2006, pI. I, fig. 13.

Remarks. We have included in this species those specimens similar to S. annulifera with broad transparent sutures, but with more inflated spherical chambers and an apiculate initial apex with a thick spine.

Siphonodosariajacksonensis (Cushman and Applin, 1926) Figs. 8.13-8.16

Nodosaria jacksonensis Cushman and Applin, 1926, p. 170, pI. 7, figs . 14-16.

Siphonodosaria abyssorum (Brady). Thomas, 1985, p. 678, pI. 14, fig. 9; Ortiz, 2006, p. 136, pI. 23, fig. 10; Fenero, 2010, p. 188, pI. 20, fig. 8.

Siphonodosaria antillea (Cushman). Takata and Nomura, 2005, pI. I, fig. 8.

Remarks. This common species is characterized by its medium to large­sized test, rectilinear to slightly arcuate, with some specimens showing a strong (- 30°) change in growth direction. Early chambers appressed, later becoming subspherical and less encompassing which exposes the apertural flange of the previous cliamber. Chambers ornamented with a row of stout basal spines. The initial apex is characterized by numerous long spines, distinctly longer in one part of the off-center area.

Siphonodosaria lepidula (Schwager, 1866) Figs. 9.5, 9.6

Nodosaria lepidula Schwager, 1866, p. 210, pI. 5, figs. 27, 28. Stilostomella sp. of Weinholz and Lutze, 1989, fig. 3A. Siphonodosaria lepidula f. lepidula (Schwager). Hayward, 2002, p. 305,

pI. 3, figs . 25-32.

Remarks. This slender species is characterized by its globular, somewhat campanulate chambers, ornamented with several rows of spines in the middle part of the chambers, extending towards the aperture as the chambers are added. The apertural flange is visible in several chambers.

Siphonodosaria longispina (Egger, 1900) Fig. 9.7

Nodosaria longispina Egger, 1900, p . 80, pI. 10, fig. 22. Siphonodosaria hispidula (Cushman). Hayward, 2002, p. 304, pI. 3, fig. 18.

Remarks. This species is characterized by squashed subspherical chambers, ornamented with strong basal spines, sometimes reaching the previous chambers and covering the constricted sutures.

Siphonodosaria pomuligera (Stache, 1864) Figs. 8.17-8.19

Dentalina pomuligera Stache, 1864, p. 204, pI. 22, fig. 3l. Siphonodosaria pomuligera (Stache). Hayward, 2002, p. 305, pI. 3, figs.

37, 38; Ortiz and Thomas, 2006, p. 134, pI. 11, fig. 7. Siphonodosaria tauricornis (Schwager). Kawagata and others, 2006, pI.

I, fig. 16.

Remarks. This species includes medium to large-size arcuate tests, with a very thick wall. Chambers are subspherical to ovate, increasing gradually in size and more inflated as added, separated by horizontal constricted sutures. They possess a very apiculate .initial apex with one or two strong pro locular spines.

Siphonodosaria subspinosa (Cushman, 1943) Figs. 9.8, 9.9

Ellipsonodosaria sp. of Cushman and Jarvis, 1934, pI. 10, figs . 4, 5. Ellipsonodosaria subspinosa Cushman, 1943, pI. 16, figs. 6, 7. Stilostomella subspinosa (Cushman). Tjalsma and Lohmann, 1983,

p. 36, pI. 14, figs. 16, 17; Thomas, 1985, p. 678, pI. 14, fig. 10; Miller and Katz, 1987, p. 138, pI. I, fig. 12.

Remarks. The species is distinguished by its subspherical-spherical chambers, more inflated as added, ornamented with numerous spines extended over the entire surface except at the top of the chamber and the apertural neck. When preserved, the long apiculate spines that make up the flange are visible.

Siphonodosaria? sp. A Fig. 8.10

Remarks. These specimens are very similar to N. longiscata, but they show a fold in the wall of the neck resulting from an apertural tooth not found in Neugeborina.

364 ORTIZ AND KAMINSKI

Genus Stiloslomella Guppy, 1894 Type species: Stilostomella rugosa Guppy, 1894

Stiloslomella rugosa Guppy, 1894 Fig. 8.5

StiloslOmella rugosa Guppy, 1894, p. 649, pI. 41 , fig. 10 (not II); Loeblich and Tappan, 1987, p. 540, pI. 585, figs. 10- 12 (not 8, 9).

Description. Test rectilinear, stout, subcylindrical, slightly tapering, initially rounded. About four distinct chambers, initially appressed, inflated and nearly spherical in the last one. Sutures horizontal, somewhat indistinct in the first chambers, distinct and depressed later. Wall calcareous, finely perforate, ornamented by numerous stout and truncate spines, becoming smaller and less distinct at the last chamber. Aperture terminal on a short neck, bordered with a lip and tooth.

Remarks. We have included these specimens in Sliloslomella following Loeblich and Tappan (1987), since Stilostomella specimens in Hayward (2002) lack an apertural phialine Lip.

Genus Strictocostella Patterson, 1987 Type species: Ellipsonodosaria modesta Bermudez var. prolata

Cushman and Bermudez, 1937

Remarks. Our specimens show an aperture on a short neck, bordered by a thick lip with one distinct tooth and long internal spines or denticles projecting downward from the base of the lip. We have included them in Striclocostella following Hayward and others (2010), although they lack a flange and show a pustular or spinose ornamentation instead of longitudinal costae.

Slriclocostella japonica (Ishizaki, 1943) Figs. 9.15- 9.18

Ellipsonodosaria japonica Ishizaki, 1943, p. 682, figs. 14, 15. Stilostomella consobrina (d'Orbigny). Thomas 1985, p. 678, pI. 14,

figs. 6, 7. Siphonodosaria lepidula f. hyugaensis (Ishizaki). Hayward 2002, pI. 3,

figs. 23, 24. Myllostomella hyugaensis (Ishizaki). Hayward and others, 2006, pI. I,

fig. 7.

Remarks. Specimens are characterized by an elongate, slender test, with chambers growing more in length than width as added, the last one(s) pyriform in shape. We have included specimens strongly ornamented with long spines (Fig. 9.16), hispid, or pus­tular (Fig. 9.15), since these differences result from the state of preservation.

Stricto costella cf. S. matanza (Palmer and Bermudez, 1936) Figs. 9.10-9.12

Ellipsonodosaria? matanza Palmer and Bermudez 1936, p. 298, pI. 18, fig. 12.

Remarks. Specimens have subspherical to ovate chambers, more inflated and less overlapping as added, and ornamented with numerous spines or pustules. This species differs from S. japonica in its less elongate test and subspherical rather than pyriform last chamber(s). However, specimens (Fig. 9.12) intermediate between this species and S. japonica are common.

Strictocostella sp. juvenile Figs. 9.13, 9.14

Remarks. We include in Strictocostella these small three-four­chambered specimens ornamented with pustules or spines, because of their similarity to the Strictocostella species recorded in Hole 647A, although their apertural features are not clearly preserved.

Family PLEUROSTOMELLIDAE Reuss, 1860

Remarks. This family includes biserial or biserial-uniserial speci­mens, with cuneate chambers. The aperture is subterminal-terminal, a straight-<:urved slit.

Genus Ellipsoidella Heron-Allen and Earland, 1910 Type species: Ellipsoidella pleurostomelloides Heron-Allen and Earland,

1910

Remarks. Aperture is subterminal, an arched slit with overhanging hoodlike margin, with an internal tube that extends from an expansion just within the aperture through the chamber to attach to the previous a pertural foramen.

Ellipsoidella pleuro.~tomelloides . Heron-Allen and Earland, 1910 Fig. 10.1

Ellipsoidella pleurostomelloides Heron-Allen and Earland, 1910, p. 410, pI. 10, figs. I-II , pI. 11, figs. 1,2; Kawagata and others, 2006, pI. I, fig. 6.

Remarks. This species tends to become uniserial, with alternating cuneate chambers. Aperture terminal, a small curved slit, without a distinct hood.

Genus Nodosarella Rzehak, 1895 Type species: Lingulina tuberosa von Giimbel, 1870

Remarks. Aperture terminal, an arcuate slit, one side slightly hooded.

Nodosarella sp. A Fig. 10.10

Remarks. Uniserial specimens, very slightly cuneate, circular in cross section. The aperture is terminal, an elongate, arcuate slit, extending diametrically through the chamber.

Genus Pleurostomella Reuss, 1860 Type species: Dentalina subnodosa Reuss, 1851

Remarks. Aperture is terminal, one side with projecting hood and opposite side partially obstructed by a flap usually with an apertural medial slit and two teeth or a bifid tooth.

PleuroslOmella acuta Hantken, 1875 Fig. 10.3

Pleurostomella acuta Hantken, 1875, p. 44, pI. 13, fig . 18.

Remarks. These specimens are similar to P. velascoensis but with a larger last chamber. Aperture characterized by a big flag with two teeth separated by a v-shaped medial slit.

Pleurostomella alternans Schwager, 1866 Fig. 10.7

Pleurostomella alternans Schwager, 1866, p. 238, pI. 6, fig. 79; Hayward, 2002, p. 302, pI. I, figs . 22- 24; Hayward and Kawagata, 2005, pI. I, figs. 4a, 4b.

Remarks. Test is slender, moderately elongate, tapered towards both ends. Chambers more inflated and elongate as added. The aperture is very similar to that of P. obtusa, with a very slightly incised, u-shaped, apertural medial slit, delimited by two pointed slender teeth. The specimens differ from typical P. alternans in the more cuneate and elongate chambers.

Pleurostomella brevis Schwager, 1866 Fig. 10.6

Pleurostomella brevis Schwager, 1866, p. 239, pI. 6, fig. 81; Jones, 1994, p. 56, pI. 51, fig. 20; Hayward, 2002, p. 302, pI. 2, figs. 25, 26; Kuhnt and others, 2002, p. 151 , pI. 12, figs . 6, 7; Hayward and Kawagata, 2005, pI. I, figs. I, 2.

Pleurostomella rapa var. recens Dervieux, 1899, p. 76.

Remarks. We follow Hayward (2002) in considering Pleurostomella brevis and P. recens to be macrospheric and microspheric forms, respectively, of the same species. This species is characterized by numerous, very overlapping and inflated chambers. A long apertural medial slit extends close to the previous chamber.

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 365

Pleurostomella obtusa Berthelin, 1880 Figs. 10.8, 10.9

Pleurostomella obtusa Berthelin, 1880, p. 29, pI. I, fig. 9; Hayward, 2002, p. 303, pI. 1, figs. 29-31.

Remarks. Test cylindrical, elongate, sides almost parallel. Chambers biserial tending to become uniserial. Apertural medial slit very slightly incised, u-shaped, delimited by two pointed slender teeth. Hayward (2002) included in this species specimens without the two apertural teeth, which were probably not preserved because of their slenderness.

Pleurostomella parviapertura Kennett, 1967 Fig. 10.4

Pleurostomella parviapertura Kennett, 1967, p. 1007,1008, pI. 998, figs. 25,26.

Remarks. This species has a very overlapping last chamber and an aperture characterized by a narrow flap with two teeth separated by an elongate medial slit.

Pleurostomella velascoensis Cushman, 1926 Fig. 10.2

Pleurostomella velascoensis Cushman, 1926, p. 590, pI. 16, fig. 4.

Remarks. Test elongate, subcylindrical, characterized by a small last chamber. Aperture almost terminal, a slightly hooded subcircular slit, located close to the suture.

Pleurostomella sp. A Fig. 10.5

Remarks. These specimens show two, inflated, subspherical chambers with a very rounded initial apex. The aperture has a big flap with two teeth separated by a v-shaped slit.

366 ORTIZ AND KAMINSKI

APPENDIX 2

Census counts, relative abundance, and stratigraphic distribution of deep-sea, calcareous, elongate-cylindrical benthic foraminifera in ODP Hole 647A. * Samples excluded from the quantitative analyses.

:: ~ on 0 00 on ~ on 0 0 ~ ~ 0 - on r- on on 00 ~ 0 ~ ~ N

" M c; on ~ c; ~ 0 on '" 00 ..,. 00 ~ '" M

Depth (mbsf) - 0 0 ~ ~ ~ Gi (;j ~ ~ :i ;g on vi on ~ ~ ~ ;0 ~ [;;l M M ;t on on '" '" '" '" '" 00 00 00

'" '" '" '" '" N N N N N N N N N N N '" '" N '" '" '" . . . r- oo § ~ N . § N 00 - ~

... :": N

~ 0 :": :": .

~ - ~ :": N r- N ;:!; '" N 00 M '" 0 ~

.,. <;- J: '" 00 on '" ~ § '" .6 ":' ,- r'- J: :b ~ '" ,-

Hole 647, core A, section, interval (cm) l" § '" :: :": ~ :: :": :": a: ~ :: :! :! ~ :": N N '" ... N r- - ... . N N rf ~ ~ ~

..f .... i ~

N'

~ ~ ~~ ~~ .... ;;:; ;;:; ~ ~ ~ ~ ~ g; ~ ..: ~ ~

;;:; ;;:; .>: .>: .>: r- r- oo 00 00 g g g g g g g g g g N N N N N N N N N

I Interval 2· EOT Interval 3 - Early Oligocene r 2a

Amphimorphinel/a amchitkaensis 4 8 I

Chrysalo~onium cf. C. chapman; 4 2 I Chrysalo;(onium I'.omphi{ormis I ChrysaloKonium polystomum 2 2 30 2 4 II 3 2 14 I Chrysa/of!onium aff. C. poiystomum Chrysa/oKonium setosum I 2 3 I Chrysalo;(onium sp. I 5 I 2 2 I Chrysalo;(onium sp. A I Chrysaioftonium spp. 4 I I I I 2 Cribronodosaria equisetiformis 2 I 3 3 2 I Cribronodosaria sp. 1 Cribronodosaria sp. 2 Cribronodosaria sp. A 3 Crihronodosaria sfimulea 5 5 4 3 4 I 2 I I 7 Cribronodosaria cf. C slimulea 3 Dentalina sp. I , I I I I I

Dentalina sp. 2 2 Dentalina sp. 3 Dentalina sp. A I I 2 2 2 2 Dentalina? spp. I

Ellipso;(/andulina spp. I I I Ellipsoidella p/eurostomelloides Ellipsoidina spp. 2

Ellipsopleuros/omella spp. I I I Ellipsopo/ymorphina schlichti Ellipsopolymorphina spp. 4 I Glandulonodosaria ambigua 3 I Glandulonodosaria trincherasensis I I 2 2 2 I

Grillelis sp. I I 2 I

GriJ!e/is spp. I 2 Neugeborina lon!{isca/a I 2 I 3 I 3 I I I 2

Neu;(eborina cf. N /onf!iscata I 2 I I 4 4 I 3 3 2 3 Neugeborina ovicula 2 1

Nodosarella sp. A 4 2 2 Orthomorphinajed/itschkai I I

Orthomorphina cf. a. ;ed/itschkai 2 Orlhomorphina spp. I

Plec/ofrondicularia sp.

Pleuros/omella acuta I 4 I 2 9 2 2 I 2 I 2

Pleuras/omelia alternans I

Pleurostomella brevis I I 1

Pleuros/omella obtusa 8 6 6 3 6 2 2 3

Pleurosfamella parviapertura 3 I I 2 2 3

Pleuros/omella sp. A I

Pleuros/omella sp. B I I 20 2 I

Pleurostomella spp. I

Pleurosfomella velascoensis I I I 2 3

Proxifrons? /labe//iformis Siphonodosaria annulifera 2 2 5 4 5 3 2

Siphonodosaria graci/lima I I 3 2 I I 2 I

Siphonodosariajacksonensis 3 2 10 3 6 5 I 3 II 6 4 6 21 7 185 2 13 26 2 Siphonodosaria /epidu/a I I I I I 3 4 2

Siphonodosaria /ongispina Siphonodosaria pomuligera 2 10 I I

Siphonodosaria? sp. A 4 I I 2 I

Siphonodosaria spp. I I Siphonodosaria subspinosa I I I 3 3 4 30 4 7 3 Species A , gen. et sp. inde! 2 I I 3 I 2 Sti/osfome//a rugosa I 3 6 I

Strictocosfe//ajaponica 5 I 1 3 I 7 3 II 3 3 3

Stric/ocostella cf. S matanza 2 2 I 9 7 3 Total benthic foraminifera n" of soecimens 94 41 0 110 384 170 144 634 97 0 0 89 0 0 137 154 42 185 57 165 60 347 353 192 412 324

Relative abundance elongated cylindrical (%) 38.3 0.0 0.0 16.4 26.0 14.1 27.8 10.944.3 0.0 0.0 19.1 0.0 0.0 21.2 13.6 11.9 14.6 0.0 30.9 35.0 76.4 5.7 18.8 18.0 10.2

Total agglutinated foraminifera (n" of specimens) 8 41 0 20 41 25 28 106 5 0 0 21 0 0 14 II 15 37 0 16 3 17 22 39 26 27

ELONGATE GP ACROSS THE EOT IN N ATLANTIC 367

APPENDIX 2 Continued .

c- ~ :i': .... N N

~ M ;; N ~ ;1; c- ~ c- '" 00 ;; :;!; c- .... 00 '" '" N :=: ~ '" M ~ ": '" ": c- oo "! 00 .... '" ": ~ .... 00 N '" Depth (mbs!) .f ~ vi ~ '" c- c- oo 00

~ '" 0 0 0; 0; 00 '" '" 0 0 00 00 '" '" 0 0 00 00 00 00 00 00 00 00 00 00 00 00 '" '" g) '" '" ;; ;; ;; ;; ;; ;; -N N N N N N N N N N N N N N N N M M M M . - c- .... ~ '" 0 0 - ~ '"

0 M '" .... c- :=: .

~ . ~ ~ M ~ ~ '" M ;; '" ~ '" 00 ~ ~ r'- ~ '" M c- M 00 B ~ .J. 'i' '" 'i '" oh :b Hole 647, core A, section, interval (cm) :=: ::: ~ ;;!; :=: ~ M .J. '" :=: ~ g; ~ ;j: ~ ~

00

~ ~ M c- M N 00 - .c, " U

~. J~ ~ ~ ~ ~~ ~~ ~~ ~~ ~ ~ ;;; ~~ ~ ~~ ;;; ;;; ;;; ~ ~ ;;; ~ ~ ~. ~ ~ ;;; ;;;

;; ;; ;; ;; ;; ;; ;; ;; ;; '" M '" M M M ~- ~ ~ ~ ~ ;:: ;J; ;;

Interval 2- EOT I Interval 1 - Late Eocene

2b I Ib

Amphimorphinella amchitkaensis 6 2 3 I I I

Chrysa/of{onium cf. C. chapman; I 5 I 3 Chrysa/oRonium Romph~formis 9 3 I

Chrysaiof{onium polyslomum 2 7 6 34 32 \0 6 \0 6 I I I

Chrysaiof{onium aff. C. po/ystomum I 3 I I Chrysaiof{onium setosum 3 5 1

Chrysalo~oni!lm sp. I 3 3 1

Chrysalo~onium sp. A I 5 5 1 I 2 Chrysa[oRonium spp. 5 2 3 3 3 2 1 1 4 4 3

Cribronodosaria equisetiformis I I 1 1

Cribronodosaria sp. 1 Cribronodosaria sp. 2 Cribronodosaria sp. A I 1 3 Cribronodosaria stimulea 2 4 4 6 4 3 4 I 3 3 Cribronodosaria cf. C. stimulea 2 2 2 I 1 2 Dentalina sp. I I I

Dentalina sp. 2 3 2 Dentalina sp. 3 I

Dentalina sp. A I I I

Dentalina? spp. - I

Ellipso~landulina spp. 2 Ellipsoidella pleurostomelloides Ellipsoidina spp. 1

Ellipsopleurostomella spp. Ellipsopolymorphina schlichti I 2 Ellipsopolymorphina spp. Glandulonodosaria ambi~a I 1 1 1 2 Glandulonodosaria trincherasens is I I

Gri~elis sp. I 2 1 1 1

Gri~elis spp. 1 Neugeborina /onf;iscata 3 I 2 I 2 I 3 3 I I I 3 I 5 2 2 1

Neu~eborina cf. N lon~iscata 3 4 3 6 1 2 3 I 3 I 1 3 3

Neugeborina DvicuJa I 2 2 I I

Nodosarella sp. A I I Orthomorphinajedlitschkai I I 1

Orthomorphina cf. 0. ;edlitschkai Orthomorphina spp. Plectofrondicularia sp. I Pleuras/omella aeula 3 2 2 1 1 3 I 2 2

Pleurostomella alternans I Pleuras/omelia brevis 2

Pleuras/omelia obtusa 2 1 1 I 2 1

Pleuras/omelia parviapertura 2 I

Pleurostomella sp. A I

Pleurostomella sp. B I I

Pleurostomella spp. I 1

Pleuras/omelIa velascoensis I

Proxifrons? f/abelliformis 6 4 3 I

Siphonodosaria annu/~fera 3 I I 1 1 1

Siphonodosaria wacillima I I I 1 4 I 2 I 6 I

Siphonoc/osariajac/csonensis I 38 I 2 2 I \0 38 14 3 7 5 1 3 2 4 2 2 6 3

Siphonodosaria lepidula I I II 20 3 2 3 4 8 I

Siphonodosaria lon~ispina I I

Siphonodosaria pomuligera I 2 I 12 3 2 2 I 2 I 2 3

Siphonodosaria? sp. A 1 I I I I 2

Siphonodosaria spp. Siphonodosaria subspinosa 12 42 14 22 34 13 10 7 I II 10 1

Species A, gen. et sp. indet I I I

Stilostomella ru~osa Strictocosle/lajaponica 5 48 6 42 8 9 3 6 34 2 I 5 2 5 I 3 6 Strictocostella cf. S. matanza \0 6 6 83 10 9 7 19 8 1

Total benthic foraminifera n° of soecimens 250 545 322 542 840 300 268 212 192 343 157 232 172 188 127 0 59 0 81 0 87 142 4 260 13 1 154 115 118

Relative abundance e longated cylindrica l (%) 16.827.7 19.3 22.3 30.0 21.0 22.0 17.526.039.4 31.8 8.2 12.8 9.0 3.9 0.0 10.2 0.0 19.8 0.0 3.4 14.1 0.0 4.2 13.7 18.820.011.9

Total agg lutinated foraminifera (n° of specimens) 27 21 9 2 13 7 24 II 29 9 12 67 67 80 94 0 27 0 43 0 57 77 0 96 67 74 67 44

ORTIZ AND KAMINSKI

APPENDIX 2 Conti nued .

00 N ~ 0 - ~ ~ 00 ~ ~ N 0 ~ ~ '" ~ ~ ~ 0 g ~ 00 iii 0

~ ~ Depth (rubs!)

M "'! '" M <- '" '<! ~ 00 '<! M 00 N '" ~ '<! '" <- <Xi 00 '" '" ~ ~ - - ~ <-

~ ~ ~ 0 N N ...: ~

00 '" '" '" ~ - ~ M ~ ~ ~ ~ ~ M M M ;t. ;t. ;t. ;t. ;t. ;t. ;t. ;t. ;t. ~ M M M M

~ - M N <- S S N ~ 0 - M ~ - N .

~ "" ~ M

~ 0

~ N

~ ~ N N

~ :6 ~ M M M

::\ ~ ';' '" J; N '" ~ ~

~ ~

~ '" ~ '" N '" Hole 647, core A, section, interval (cm) to ;::; ~ M '" N ~ '" - '" '" ~ :;:: 11: '" ~ 11: N <- N "" "" - "" - "" - '" U

~ ~ g ~" ~" ~ ~ ~" ..: ;;; ;;; ~~ ~ ~" ~ '1' ~ ~ ;;; <f ~. N ~~ ~~ ~" .,." ~ ~ ~ '" ~ ~ ~ ;t. ;>: ;>: ;>: ;>: ;>: ;>: ;>: ~ ~ ~

Interval 1 - Late Eocene

la

Amphimorphinella amchitkaensis Chrysaio1!onium cf. C. chapman; Chrysalof(onium f(omphi(ormis 1 ChrysaloKonium polystomum 2 2 1 I I 1

Chrysaio1!oniurn aff. C. polystomum Chrysaiof.{onium setosum 1 3 1 Chrysaio1!onium sp. 1 Chrysalo"onium sp. A 2 Chrysa/o).!onium spp. I 4 1 2 4 3 5 3 Cribronodosaria equisetiforrnis 1 1 1 2 1 1 Cribroflodosaria sp. 1 1

Cribronodosaria sp. 2 1 Cribronodosaria sp. A Cribronodosaria stimulea 3 2 9 8 5 2 7 2 8 3 7 7 5 2 8 3 3 2 1 10 6 Cribronodosaria cf. C. stimuleq 2 3 1 3 4 3 2 1 1 7 Dentalina sp. I 1 Dentalina sp. 2 I 1 4 4 Dentalina sp . 3 2 1

Dentalina sp. A 1 2 4 1 1 1 Dentalina ? spp.

/ 2

Ellipsof(landulina spp. I I Ellipsoidella pleurostomelloides 1 5 1 1 2

Ellipsoidina spp. 1 Ellipsopleurostomella spp. 4 1 Ellipsopolymorphina schlichti Ellipsopolymorphina spp. I 1 1

Glandulonodosaria ambif(Ua 1 2 1 2 2 1 Glandulonodosaria Irincherasensis 1 2 2 3 2

Gri"elis sp. 1 1 1

Gri"elis spp. 1

Neuxeborina lonKiscata 4 3 1 2 2 2 2 2 3 3 2 3 2 1 2 5 1 3 3 1 1

Neu£eborina cf. N. lon~iscata 1 1 3 I 2 3 2 1 2 2 2 2 1 3 2 5 2 Neuf(eborina ovieula 1

Nodosarella sp. A 1 1 2 1 2

Orthomorphinajedlitschkai 1 1 1 I

Orthomorphina cf. 0. jedlitschkai 2 2 1

Orthomorphina spp. 1 1 1

Plectofrondicularia sp.

Pleurostomella aeuta 3 4 3 3 1 1 I 1 3 2

Pleurostomella alternans 1

Pleurostomella brevis 1 2 2 1 1 1 1

Pleurostomella obtusa 2 3 4 2 1 2 1 1 2 1 1 1 1

Pleurastomella parviapertura 1 1 1

Pleurostomella sp. A 3 2 7 5 5

Pleurostomella sp. B 1 1 2

Pleurostomella spp. 1 2 1 1

Pleurostomel/a velascoensis Proxi{rons ?.f/abelli(ormis Siphonodosaria annu/~fera 1 1 1

Siphonodosaria f(racillima 3 2 1 1 4 1 4 1 1 3

Siphonodosariajac/csonensis 12 7 14 16 9 4 10 7 16 13 8 4 4 1 14 19 6 1 1 4 2 6 27 4 10

Siphonodosaria lepidula 1 2 1 1 1 5 1 2 1 1 3 6 I 2 1

Siphonodosaria lonJ(ispina 1

Siphonodosaria pomuliJ(era 1 2 2 t 4 1 1 1 1 1 3 1 1

Siphonodosaria? sp. A 2 1 I 3 1 1 I Siphonodosaria spp. 2 6 14 1 2 2 4

Siphonodosaria subspinosa 2 4 5

Species A, gen. et sp. indet 2

Stilos /omelIa rUJ(osa Strictoeostellajaponica I 1 3 I 1 2 2

StrictocostelIa cf. S. matanza 1 8 1 2 8 1 5 2 1 1 2 2 Total benthic foraminifera (n' of specimens) 36 199 11 6 514 241 121 344 236 217 42 1 204 276 592 151 194 136 315 100 139 240 91 132 41 46 206 282 119 196

Relative abundance elongated cylindrical (%) 44.4 11.1 28.4 13.4 16.6 14.9 13.4 10.2 14.7 13.1 16.2 6.9 8.6 9.3 14.922.8 18.4 13.0 11.5 9.6 23.1 7.6 22.0 10.9 12.1 20.9 12.62 1.9

Total agg lutinated foraminifera (n" of specimens) 0 68 32 180 89 44 148 98 48 129 70 105 180 68 72 58 150 32 81 107 27 54 26 20 93 118 36 91