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ISSN: 0191-6122 (Print) 1558-9188 (Online) Journal homepage: http://www.tandfonline.com/loi/tpal20

New species from the Sabrina Flora: an early and assemblage from the Sabrina Coast, East

Catherine Smith, Sophie Warny, Amelia E. Shevenell, Sean P.S. Gulick & Amy Leventer

To cite this article: Catherine Smith, Sophie Warny, Amelia E. Shevenell, Sean P.S. Gulick & Amy Leventer (2018): New species from the Sabrina Flora: an early Paleogene pollen and spore assemblage from the Sabrina Coast, East Antarctica, Palynology, DOI: 10.1080/01916122.2018.1471422 To link to this article: https://doi.org/10.1080/01916122.2018.1471422

Published online: 12 Dec 2018.

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Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=tpal20 PALYNOLOGY https://doi.org/10.1080/01916122.2018.1471422

New species from the Sabrina Flora: an early Paleogene pollen and spore assemblage from the Sabrina Coast, East Antarctica

Catherine Smitha, Sophie Warnyb, Amelia E. Shevenella, Sean P.S. Gulickc and Amy Leventerd aCollege of Marine Science, University of South Florida, St. Petersburg, FL, USA; bDepartment of Geology and Geophysics and Museum of Natural Science, Louisiana State University, Baton Rouge, LA, USA; cInstitute of Geophysics and Department of Geological Sciences, University of at Austin, Austin, TX, USA; dDepartment of Geology, Colgate University, Hamilton, NY, USA

ABSTRACT KEYWORDS Palynological analyses of 13 samples from two sediment cores retrieved from the Sabrina Coast, East ; ; Aurora Antarctica provide rare information regarding the paleovegetation within the Aurora Basin, which Basin; Sabrina Coast; East today is covered by the East Antarctic Ice Sheet. The assemblages, hereafter referred to as the Sabrina Antarctica; Gambierina; Flora, are dominated by angiosperms, with complexes of Gambierina (G.) rudata and G. edwardsii rep- Battenipollis resenting 38–66% of the assemblage and an abundant and diverse Proteaceae component. The Sabrina Flora also includes Battenipollis sectilis, Forcipites sp. and Nothofagidites (N.) spp. (mostly belonging to the N. cf. rocaensis-cf. flemingii complex), along with a few , including Laevigatosporites ovatus, a moderate presence of , and previously undescribed angiosperm morphospecies. Two of these, Battenipollis sabrinae sp. nov. and being Gambierina askiniae sp. nov., are described herein. A majority of the assemblage is interpreted as deposited contemporaneously with sedimentation, including Gambierina spp., which is traditionally assigned a –earliest Eocene age range. However, our age diagnosis for the Sabrina Flora, based on key morphospecies, indicates that sediment was most likely deposited between the latest Paleocene to early–middle Eocene, and that Gambierina rudata and G. edwardsii extended longer than previously proposed.

1. Introduction sequence, marine sediment cores were collected from out- cropping seismic reflectors in the lower part of the sequence The Aurora Subglacial Basin (ASB), one of the three largest and surrounding the regional unconformity at the base of subglacial basins in East Antarctica, is drained by large outlet Megasequence III. These data reveal a history of cli- glaciers terminating at the Sabrina Coast (115˚ to 121E and mate and environmental change within the ASB catchment, 67 S), East Antarctica (Figures 1 and 2, Ferraccioli et al. 2009; including a record of ice advance and retreat that suggests Young et al. 2011; Fretwell et al. 2013; Rignot et al. 2013; the EAIS is more sensitive to climate change than tradition- Greenbaum et al. 2015; Aitken et al. 2016). The region is ally thought (Gulick et al. 2017). presently sensitive to climate change, as indicated by the Two jumbo piston cores (JPC; NPB 14-02 JPC-54 and JPC- thinning and retreat of local outlet glaciers influenced by 55, see Figures 1–3 for locations) retrieved from the lower- warm modified Circumpolar Deep Water driven onto the most preglacial Sabrina Coast sediments (Megasequence I) Sabrina Coast continental shelf as westerly winds shift south- contain an abundant, diverse, and well-preserved terrestrial ward (Rintoul et al. 2016; Greene et al. 2017). Past regional palynomorph assemblage, as first reported in Gulick et al. climate sensitivity is also suggested by ice sheet and climate (2017). Here we detail this new terrestrial palynological models and marine geological observations, which indicate assemblage, termed the Sabrina Flora, and describe two pre- that ice caps may have nucleated in the Gambertsev viously undescribed species discovered in the Sabrina Coast Mountains and first reached the Sabrina Coast and Prydz Bay sediments. The Sabrina Flora provides a rich paleobotanical prior to continental scale Antarctic glaciation in the latest archive of the ASB catchment before and during ice sheet Eocene (DeConto and Pollard 2003; Gulick et al. 2017). development and adds to the available Paleogene East In 2014, the first marine seismic and geological investiga- Antarctic margin terrestrial palynomorph records from Prydz tions of Sabrina Coast continental shelf sediments were con- Bay (e.g. Macphail and Truswell 2004; Hannah 2006; Truswell ducted as part of the Antarctic Program RV/IB and Macphail 2009), the Shackleton Ice Shelf region (Truswell Nathaniel B. Palmer cruise NBP 14-02. From the resulting geo- 1983, 2012), the Wilkes Land margin (Domack et al. 1980; physical data, Gulick et al. (2017) identified three seismic Truswell 1983; Schrum et al. 2004; Pross et al. 2012; stratigraphic intervals, termed Megasequence I, II, and III Contreras et al. 2013), and the Ross Sea region, including the (Figure 3), interpreted to reflect pre-glacial, meltwater-rich McMurdo Erratics (Askin 2000; Levy and Harwood 2000) and glacial, and polar glacial environments, respectively. To con- McMurdo Sound (Truswell 1983; Mildenhall 1989; Hannah strain the age of the Sabrina Coast shelf sedimentary et al. 1998; Askin and Raine 2000; Raine and Askin 2001;

CONTACT Sophie Warny [email protected] Geology and Geophysics, E235 Howe Russell Geoscience Complex, Baton Rouge 70803, US ß 2018 AASP – The Palynological Society

Published online 12 Dec 2018 2 C. SMITH ET AL.

90°E 120°E

Eucla

Indian Bremer

Ocean Bremer Eyre Bight C ed 60°S una

NBP14-02 JPC-54, -55 1166 Prydz Murray Bay Otway 60°E Aurora Subglacial U1356 150°E Basin Gi NBP01-01 Ba ppsland s s

DF79-38 Sorell

South Tasman Rise Antarctica Pacific 30°E 50 Ma Ocean

McMurdo erratics 600 km Figure 1. Paleogeographic reconstruction of the Australo-Antarctic Gulf at 50 Ma (modified from the Ocean Drilling Stratigraphic Network (ODSN); Hay et al. 1999; van Hinsbergen et al. 2015). Sedimentary basins, including those with published pollen records of equivalent age, are indicated. Study location indicated by an open circle.

respectively (Figure 3). Both cores recovered 20–40 cm of late greenish gray diatom-rich mud (Unit I) with a sharp lower contact separating Unit I from Unit II (Figure 4). In core JPC-54, Unit II consists of sandy mud to diamict with angular igneous clasts interpreted as ice-rafted debris (IRD) (Gulick et al. 2017), while Unit II in JPC-55 consists of mica- rich mud with siderite concretions, including one 10 cm in diameter, and pyrite nodules (Figure 4). The sediments in both cores were recovered from strata stratigraphically below the first seismic evidence of grounded ice on the Sabrina continental shelf (Gulick et al. 2017). Thus, core JPC-55 sediments record the pre-glacial environment in the Aurora Basin prior to regional glaciation, while those in core JPC-54 reflect a environment where marine terminating gla- ciers were present, but ice had yet to advance onto the shelf.

3. Methods 3.1. Palynology To quantify absolute abundance of terrestrial palyno- Figure 2. Multibeam bathymetry of Sabrina Coast continental shelf collected during NBP14-02 (modified from Gulick et al. 2017; Fernandez et al. 2018). morphs and assign ages to Unit II in cores JPC-54 and JPC- Locations of sediment cores JPC-54 and JPC-55 (black circles) and seismic line 55, nine and eight samples, respectively, were split and 17 (black line) are indicated. Inset: Map of the Sabrina Coast shelf with location processed at Global Geolab Limited (Alberta, ) to and orientation of the NBP14-02 study area indicated by the multibeam data and sesimic survey lines. MUIS ¼ Moscow University Ice Shelf. (modified from extract terrestrial palynomorphs. Note that the two top Fretwell et al. 2013). samplesineachcorearenotdiscussedinthispaperas these represent modern deposition above an erosional sur- Prebble et al. 2006; Warny et al. 2009; Feakins et al., 2012; face (Figure 4). For each sample, 5 g of dried sediment Griener et al. 2013; Griener and Warny 2015). was processed using standard techniques. Acid soluble minerals (carbonates and silicates) were digested in HCl, 2. Stratigraphic context HF, followed by controlled oxidation. The residues were then rinsed to neutrality. Residues were concentrated by Cores JPC-54 (121 cm) and JPC-55 (170 cm) were collected filtration on a 10 lmmeshsieveandspikedwithaknown above and below a prograding clinoform in Megasequence I, quantity of Lycopodium spores to allow quantitative PALYNOLOGY 3

CDP 500 1500 2500 3500 4500 5500 6500 7500 8500 9500 10500 11500 12500

Line 17 landward MS-III 0.50 first grounded JPC-55 clinoforms JPC-54 ice MS-II

MS-I 0.75

multiple 1.00 Two-way traveltime (sec) Two-way SSW NNE km 0 6.25 12.50 18.75 25.00 31.25 37.50 Figure 3. Seismic image collected on NBP14-02 utilized to target JPC-54 and 55 sites. Seismic line NBP14-02 Line 17 illustrates erosional surfaces and clinoforms. JPC-54 and JPC-55 are above and below these clinoforms, respectively. After Gulick et al. (2017). / 3.2. Taxonomy Taxonomic evaluation of palynomorphs was done via lit- Core x-ray accessories image Core Graphic Sed. structures Lithologic unit lithology Disturbance Samples image Core Lithologic unit Core x-ray Graphic lithology Sed. structures/ accessories 0 Disturbance Samples 0 erature review (e.g. Cookson 1950; Cookson and Pike 1954;Couper1960; Stover and Partridge 1973;Truswell 1 1983; Jarzen and Dettmann 1992; Macphail and Truswell 1 20 20 2004;Houetal.2006;TruswellandMacphail2009; Raine et al. 2011;Prossetal.2012; Contreras et al. 2013) and using collections curated at the Louisiana State University Center for Excellence in Palynology 40 40 (CENEX). The slides and residues discussed in this paper are curated at CENEX.

60 60 4. Results 2 Depth (cmbsf) The Sabrina Coast sediments yielded abundant, diverse, and

80 80 well-preserved palynomorphs. Palynomorph concentrations ranged from 3540 to 6560 grains per gram dry sediment (gdw1) for core JPC-54 and from 4200 to 8570 gdw1 for Depth (cmbsf) core JPC-55, with a mean of 4330 gdw1 and 6390 gdw1, 100 100 respectively. These concentrations indicate that Sabrina 2 Coast sediments are rich in palynomorphs relative to other Antarctic sediment sequences. The Sabrina Coast assemb-

120 120 lages provide a first glimpse into the terrestrial environment NBP 14-02 JPC-54 of the Aurora Basin before the EAIS expanded to its current

Lithology Structures/ continental-scale configuration. Accessories mud inclined contact Cores JPC-54 and JPC-55 are distinguished from one sandy mud clast cluster 140 P pyrite another by differences in their respective palynological diatom-rich nodule siderite gravel-rich S concretion assemblages. The JPC-55 assemblage contains 16–23% fish tooth Coring disturbance gastropod Battenipollis sabrinae sp. nov. (formally described below), a flowage bivalve slight 160 previously undescribed angiosperm pollen species similar to moderate soupy Battenipollis sectilis. In contrast, only one sample from core flow-in JPC-54 (46–47 cm) contains Battenipollis sabrinae sp. nov. (2% NBP 14-02 JPC-55 of the total assemblage). Core JPC-54 also contains a higher Figure 4. Core photographs and lithologic logs from jumbo piston cores total abundance of Nothofagidites spp. (5–12%), compared to NBP14-02 JPC-54 and JPC-55, modified from Gulick et al. (2017). Pollen sample locations indicated by open circles. 1-3% of the JPC-55 assemblage. Core JPC-54 sediments con- tain N. emarcidus and N. cranwelliae, which were not observed in core JPC-55. Despite these differences, similarities exist between the assessment of terrestrial palynomorph concentrations. At two assemblages. In both cores, the palynological assem- least 300 terrestrial palynomorphs were counted per sam- blage is dominated (38-66%) by Gambierina rudata, G. ple using a transect method. All terrestrial palynomorphs edwardsii, and related complexes. Proteaceae (7–17%) are were identified using a Zeiss Axio Vert-A1 inverted micro- diverse, consisting mostly of Proteacidites tenuiexinus. This scope with a 100x oil immersion lens. angiosperm-dominated assemblage also includes Battenipollis 4 C. SMITH ET AL.

Plate 1. Age diagnostic pollen morphospecies from NBP14-02 JPC-54 and JPC-55. 1-4) Battenipollis sabrinae sp. nov. 5-8) Gambierina askiniae sp. nov. 9-10) Gambierina spp. clusters 11) Forcipites longus 12) Phyllocladidtes mawsonii 13) Laevigatosporites ovatus 14) Battenipollis sectilis 15) Gambierina edwardsii 16) Gambierina rudata 17) Proteacidites tenuiexinus 18) Nothofagidites flemingii-rocaensis complex 19) Nothofagidites emarcidus. PALYNOLOGY 5

Plate 2. Scanning electron microscope (SEM) images of new Sabrina Coast species. 1) Battenipollis sabrinae sp. nov 2) Gambierina askiniae sp. nov. The microphoto- graph dimensions indicated are those of the specimens illustrated. Specimens of Battenipollis sabrinae sp. nov range from 23 to 31 microns (lm) and specimens of Gambierina askiniae ranged from 23 to 33 lm. sectilis, Forcipites spp. and Nothofagidites spp. (mostly the N. Dimensions. Diameter of 15 specimens from core JPC-55: 23 cf. rocaensis-cf. flemingii complex). pollen grains are (28) 31 mm present (3–10%), including Phyllocladidites mawsonii, The mean distal exine thickness is 2.5 mm. Microcachryidites antarcticus, and Microalatidites paleogenicus, Remarks. Battenipollis sabrinae sp. nov. is distinguished from as are fern spores [e.g. Laevigatosporites ovatus (1–8%)]. Battenipollis sectilis by a thicker exine (2-3 mmvs<2 mm) and Because of the similarities between cores JPC-54 and JPC-55, the highly irregular coarse rugulate sculpturing between aper- we refer to the palynoflora assemblage as the Sabrina Flora, tures. Specimens vary in width of apical protuberance. named after the Sabrina Coast. Etymology. Battenipollis sabrinae is named for the Sabrina Coast of East Antarctica where the morphospecies is first described. 5. Systematic palaeontology Anteturma POLLENITES H. Potonie 1893 Turma POROSES Naumova 1937-39 Anteturma POLLENITES H. Potonie 1893 Subturma TRICOLPORATES Iversen and Troels Smith, 1950 Turma POROSES Naumova 1937-39 Genus Gambierina Harris 1972 emend. Stover & Partridge Subturma TRICOLPORATES Iversen et Troels Smith 1950 (1973); emend. Jarzen & Dettmann 1992 Genus Battenipollis Jarzen & Dettmann 1992 Type species. Gambierina edwardsii Stover in Stover & Type species. Triporopollenites sectilis Stover in Stover & Partridge (1973) Partridge 1973 Gambierina askiniae sp. nov. Battenipollis sabrinae sp. nov. Plate 1, images 5-8; Plate 2, image 2 Plate 1, images 1-4; Plate 2, image 1 Holotype. Plate 1, image 5. Holotype. Plate 1, image 1. Type locality. Offshore of the Sabrina Coast, East Antarctica Type locality. Offshore of the Sabrina Coast, East Antarctica (S66˚20.998 E120˚30.454) (S66˚20.998 E120˚30.454) Diagnosis. Pollen tricolporate, amb triangular to concavely Diagnosis. Pollen tricolporate, angulaperturate, amb concavely triangular, apertures rounded, apertures smooth. Exine 1–2.5 to slightly convex triangular between apertures, apertures broadly mm thick, vaguely differentiated, sexine thicker than nexine, rounded to truncate, apices smooth. Exine 2–3 mmthick,vaguely with sexine smooth at apertures and mostly irregularly to moderately well differentiated, sexine thicker than nexine, roughened to coarsely rugulate between apertures. Exine slightly thicker in interradial areas, with sexine coarsely rugulate may be slightly thickened at pores, with well-defined nick ontheentiresurfaceofthegrainapartfromtheapertureareas point within the apertures. that are mostly psilate to finely rugulate. This consistently coarse Dimensions. Diameter of 16 specimens from core JPC-55: 23 texture is one of the key features of this species of Battenipollis. (26) 33 mm 6 C. SMITH ET AL.

NBP14-02 JPC-54 and JPC-55 species based on various studies. A recent study by 34 Contreras et al. (2014) published a robust LAD for these spe- ? ? 38 late cies at the Paleocene/Eocene boundary at ODP Site 1172, on the East Tasman Plateau. However, Partridge (1999) noted 42 that in southeastern Australia, the ranges of the two 46 middle Gambierina species extend into the earliest Early Eocene.

50 Eocene Extended ranges for the Gambierina sp., indicated in Figure 5

Nothofagidites cranwelliae Nothofagidites emarcidus by dashed-lines, are based on the palynological analysis of ~56−38 Ma

54 early Nothofagidites lachlaniae N. flemingii-rocaensis complex Proteacidites tenuiexinus Ocean Drilling Program (ODP) Site 1166 in Prydz Bay 58 (Macphail and Truswell 2004; Truswell and Macphail 2009), Microalatidites paleogenicus

Age (Ma) where the authors postulate that the abundant well-pre- ml 62 ~59.2−56 Ma served Gambierina specimens are unlikely recycled and argue Dilwynites granulatus Phyllocladidites mawsonii Laevigatosporites ovatus early 66 Paleocene that their range should be extended into the early to middle Legend Eocene in Prydz Bay (see additional discussion regarding 68 JPC-54 & 55 pollen Gambierina in section 7). Microalatidites paleogenicus is listed

Gambierina edwardsii Gambierina rudata JPC-54 pollen 70 last occurence with a range of Paleogene to in a detailed sum- Late extended range Cretaceous mary by Raine et al. (2011). There is some divergence of 74 opinion regarding this range; Macphail (in Hill 1994) lists the Figure 5. Biostratigraphic range chart summarizing age diagnostic pollen mor- phospecies. Additional data added to that published in Gulick et al. (2017). first occurrence of Microalatidites paleogenicus as Senonian in Australia and , but there is no robust evidence The mean distal exine thickness is 1.5 mm. supporting an extended range in Antarctica. However, Remarks. Gambierina askiniae is distinguished from Microalatidites paleogenicus is listed in Fossilworks (PaleoDB Gambierina rudata by a lack of extreme thickening of the number: 321781) as having a range from 55.8 to walls at the aperture level and different wall texture. 11.608 Ma. Nothofagidites lachlaniae has a range from Gambierina askiniae differs from Gambierina edwardsii by Paleogene to modern while the Nothofagidites flemingii- having less concave sides, rounder apertures, smaller diame- rocaensis morphotype has a range from Paleogene to ters, and an irregular, moderately to coarsely rugulate sculp- Neogene according to the comprehensive summary by Raine tured exine between the apertures. Gambierina askiniae et al. (2011). Truswell (1983) lists the range for N. lachlaniae should include a specimen described as Gambierina sp. A in in New Zealand as to present day and notes Jarzen and Dettmann (1992). Truswell (1983) illustrated a similarity to other forms. Regarding the variability found in morphotype described as Gambierina sp., recovered from Nothofagidites ranges in the Paleocene and Eocene, some of reworked sediments sampled from the West Ice Shelf and the variation observed is undoubtedly climatically induced. Shackleton Ice Shelf. These specimens also have an exine For example, Pocknall (1989) argued that broad regional that is rugulate, but much coarser than that of G. askiniae, changes in vegetation (e.g. the abundance of Nothofagidites and the exine is more heavily thickened around the aper- lachlaniae in western Southland (Ohai, Waiau and Balleny tures. The overall size of Gambierina sp. of Truswell (1983)is basins) and its scarcity in other Eocene sections from larger, ranging between 33 and 41 mm. It is possible that Waikato, the Taranaki Basin, and the west coast of New Gambierina sp. of Truswell (1983) and G. askiniae sp. nov. are Zealand’s South Island) are related to paleoenvironmental variations within this species population. factors. The type material is (Dettmann et al. 1990), Etymology. Gambierina askiniae is named for Dr. Rosemary but the distinction of this species from other Fuscospora pol- Askin, in recognition of her mentoring of Antarctic palynolo- len (including N. brachyspinulosa and N. waipawaensis)is gists and for her contribution to Antarctic palyno- problematic. If N. waipawaensis and N. senectus are excluded, logical research. then the New Zealand FAD of other Fuscospora pollen would be late Paleocene (Ian Raine, pers. comm.). Regarding N. fle- mingii, Raine (pers. comm.) stated that in Southern Australia, 6. Age Interpretation and significance Stover and Partridge (1973) and Stover and Evans (1973) put The palynological biostratigraphic zonation of cores JPC-54 the FAD of N. flemingii in the upper part of their and JPC-55 is based on the presence of a few key species Lygistepollenites balmei Zone, which is late Paleocene. Harris and limited data available from Antarctica and surrounding (1965) did not report the species in his detailed study of regions (e.g. Australia and New Zealand). The age assign- Paleocene-Eocene transition strata in western Victoria. In ments for these cores are discussed in the Supplemental New Zealand, the FAD was reported as middle Eocene in Information published in Gulick et al. (2017). A summary of Couper (1960) and Raine (1984). Pocknall (1989) notes that, the discussion is as follows: Phyllocladidites mawsonii, by the late Eocene (Kaiatan stage) in New Zealand, Casuarina Dilwynites granulatus and Laevigatosporites ovatus are known and Nothofagidites flemingii predominate the assemblage, from various sources to range at least from Late Cretaceous together with several Proteaceae, including Proteacidites through Eocene and thus, they do not allow narrowing of asperatus, P. incurvatus, and P. reticulatus. But going back to the age range beyond 74 to 34 Ma. Gambierina edwardsii and the FAD, Raine (pers. comm.) recently observed occasional Gambierina rudata are known as Cretaceous to Paleocene specimens throughout the early Eocene from well-dated PALYNOLOGY 7 outcrop localities in New Zealand. However, these specimens clusters of both G. rudata and G. edwardsii species, with up are smaller than the typical N. flemingii and there is an to 40 specimens per cluster, in cores JPC-54 and JPC-55 ongoing debate as to their taxonomic affiliation. Thus, we (Plate 1, images 9-10). Both lines of evidence suggest that follow early recommendations and place the FADs of both these specimens were deposited close to the angiosperm species in the late Paleocene. Proteacidites tenuiexinus has a parent , indicating most Gambierina specimens are not range from 66.043 to 15.97 Ma (PaleoDB taxon number: reworked, and are therefore penecontemporaneous with 277519 at fossilworks.org). However, Stover and Partridge sedimentation. (1973) list the Proteacidites tenuiexinus FAD as late Paleocene Although South Australian and New Zealand reports (ref- in southeastern Australia. We follow Stover and Partridge erenced above) define the age range of Gambierina spp. as (1973), but acknowledge that the FAD could be as early as Late Cretaceous–late Paleocene/earliest early Eocene, early Paleocene. Truswell and Macphail (2009) suggested that Gambierina spp. Several well-preserved specimens of Forcipites longus and likely extended through the late Eocene in Prydz Bay, East Battenipollis sectilis were also identified. Because of the con- Antarctica. Pross et al. (2012) also suggest that the parent troversial nature of these species LADs, they are not used in plant for Gambierina edwardsii survived during the Early and the biostratigraphic zonation. While an extended range to middle Eocene along the Wilkes Land coast, as observed at the Eocene is proposed in Antarctica based on well-pre- Integrated Ocean Drilling Program (IODP) Site U1356. Pross served specimens from Prydz Bay, questions remain about et al. (2012) argued that the longevity of Gambierina spp. in reworking within the sequence (Macphail and Truswell 2004; East Antarctica may reflect perennially cool to cold climates Truswell and Macphail 2009). In Australia’s Gippsland Basin, in Antarctica since the late Paleocene, while a rapidly warm- Partridge (2006) places the LAD of F. longus and B. sectilis at ing climate in southern Australia during the the Cretaceous-Paleogene (K/Pg) boundary. While we do not Paleocene–Eocene Thermal Maximum could have eliminated use these species in our biostratigraphic zonation, their pres- Gambierina parent there (Macphail et al. 1994; ence may indicate that the proposed extended range in Truswell and Macphail 2009). Because Gambierina spp. were Macphail and Truswell (2004) is correct. likely living penecontemporaneously with sediment depos- Thus, based on the pollen assemblage alone, we favor a ition at the sites of cores JPC-54 and JPC-55 on the Sabrina Paleocene to earliest early Eocene age for core JPC-55. The Coast, and because we find at least one morphospecies in presence of benthic foraminifer species that go extinct in the our assemblage with a FAD in the early Eocene latest Paleocene and those that evolve in the Paleocene in (Nothofagidites emarcidus) only in JPC-54, we suggest that core JPC-55 enable us to further narrow the age of JPC-55 to Gambierina edwardsii and G. rudata could extend into the late Paleocene (Gulick et al. 2017). early Eocene (based on our data), and possibly to the Two pollen species were present in core JPC-54 that were middle-late Eocene if Truswell and Macphail (2009) and Pross not observed in core JPC-55, Nothofagidites cranwelliae and et al. (2012) are correct. Thus, we extend the potential age N. emarcidus. Most verified references for N. cranwelliae and range for JPC-54 into the middle Eocene, in consideration of N. emarcidus (e.g. those with specimens properly identified; these two studies (Figure 5). Furthermore, extending the the Nothofagidites group is diverse, complex, and easily misi- ranges of Gambierina edwardsii and G. rudata to the middle dentified) place the FAD of both of these species in the early Eocene is consistent with evidence for regional marine termi- Eocene, at the earliest. For instance, in Australia’s Gippsland nating glaciers (e.g. Scher et al. 2014; Gulick et al., 2017; Basin, Greenwood et al. (2003) observe abundant (50-60% of Passchier et al. 2017). the total assemblage) N. emarcidus at the early-middle In the Sabrina Coast assemblage, there are additional Eocene boundary. Stover and Partridge (1982) also found morphospecies with unknown paleobotanical affinity, includ- this species in the Eocene of western Australia. Thus, based ing: Battenipollis sectilis (renamed by Jarzen and Dettmann on the pollen assemblage alone, we favor an early to middle 1992 from Triporopollenites sectilis in Stover and Partridge Eocene age for core JPC-54. The presence of IRD in the same 1973) and Forciptes spp. Specimens of Gambierina spp., core is then a critical observation that suggests that glaciers Battenipollis sectilis, and Forcipites spp. have all been found had reached the ocean, at least locally within the Aurora within upper Cretaceous sequences in the Otway Basin Basin, by the early to middle Eocene. However, the presence (Figure 1), where they are compared to pollen of the of the pollen denotes the presence of an ecosystem within Northern Hemisphere Normapolles type (Jarzen and the catchment and, thus, only partial glacial cover. Dettmann 1992). Although there are similar morphological characteristics with the Normapolles, which are breviaxial, transcolpate and have a triangular amb (Batten 1981; Batten 7. Further discussion on Gambierina spp. and and Christopher 1981), closer analyses revealed that these paleobotanical affinity of abundant species genera evolved separately, and thus any paleobotanical affin- Gambierina spp., the most abundant (38–58%) pollen in ity is speculative (Jarzen and Dettmann 1992). These three cores JPC-54 and JPC-55, present certain issues when deter- genera (Gambierina, Battenipollis and Forcipites) likely grew mining our age assignment and paleoenvironmental inter- within forest communities adjacent to, or fringing, an estuary pretation of the Sabrina Coast sediments. Most of the (Dettmann and Jarzen 1988); however, their parent plants Gambierina spp. specimens in cores JPC-54 and JPC-55 are and affinities are still unknown. Although specimens of light in color and well-preserved. Furthermore, there are Battenipollis sectilis and Battenipollis sabrinae sp. nov. might 8 C. SMITH ET AL. be in situ, a lack of additional in situ evidence, such as clus- were collected. She presented her preliminary results at the 2015 Annual ters like those of Gambierina spp., prevents a similar age Geological Society of America-American Association of Stratigraphic Palynologists (AASP) joint meeting in Baltimore where she received the extension for Battenipollis spp. at the Sabrina Coast. Vaughn Bryant Best Student Poster award and Best Overall Poster Additional study is required to define whether Battenipollis by AASP. sabrinae sp. nov. extends to the Eocene. Furthermore, most SOPHIE WARNY is an Associate Professor and the Forcipites longus specimens are dark in color and often bro- AASP Chair of palynology in the Department of ken. Therefore, we speculate that this species is possibly Geology and Geophysics, and a curator at the reworked from Cretaceous or early Paleocene sources. Museum of Natural Science at Louisiana State University (LSU) in Baton Rouge, Louisiana, USA. Sophie received her PhD from the Université 8. Conclusions Catholique de Louvain, in Belgium, working with Jean-Pierre Suc; her doctoral dissertation was on The terrestrial palynomorphs preserved in cores JPC-54 and the Messinian Salinity Crisis. Since graduating, she has specialized in JPC-55 collected offshore of the Sabrina Coast are well-pre- Antarctic palynology and worked on Antarctic projects such as ANDRILL SMS, SHALDRIL and WISSARD. In 2011, she received the served, diverse, and likely deposited contemporaneously with National Science Foundation CAREER award to support her research sedimentation from the Aurora Basin catchment (now the in Antarctica. In addition to her research, Sophie teaches historical Aurora Subglacial Basin) deposited on the Sabrina Coast con- geology, palaeobotany and micropalaeontology. Since being hired at tinental shelf. The assemblages found within cores JPC-54 LSU, Sophie has graduated eighteen master and doctoral students; most are employed either in the oil and gas industry, as instructors and JPC-55, now referred to as the Sabrina Flora, provide at universities or with the U.S. Department of Homeland Security. valuable insight to the paleoflora, including the description AMELIA SHEVENELL of two undescribed morphospecies, Battenipollis sabrinae sp. is an Associate Professor at the University of South Florida in the College of nov. and Gambierina askiniae sp. nov. We also report on the Marine Science. She has conducted paleoceano- paleoenvironments of this previously unstudied region of graphic and paleoclimatologic research in East Antarctica, with core JPC-55 likely recording a pre-glacial Antarctica and the Southern Ocean since 1995. environment and core JPC-54 recording an environment with Her research interests include the Cenozoic evolu- tion of Antarctica's ice sheets on million year to marine terminating tidewater glaciers, and incomplete gla- decadal timescales. She uses geochemical and cial cover. foraminiferal paleoceanographic proxies from continental margin and deep-sea sediments to investigate the importance of ocean-ice inter- actions to ice sheet development. In 2006, she was awarded the GSA Acknowledgements Storrs Cole Memorial Research Award for significant publications in invertebrate micropaleontology. She began working in the Australo- The authors thank the NBP 14-02 Scientific Party, ASC technical staff, Antarctic Gulf in 2000, as a sedimentologist on Ocean Drilling and Edison Chouest Offshore crew. We remember E.W. Domack, who Program Leg 189. She is actively involved as both a scientist and an passed away in November 2017, and acknowledge his contribution. We advisory committee member in international scientific drilling initia- extend our thanks to Rosie Askin for her insight on Antarctic palynology. tives, including the Integrated Ocean Discovery Program (IODP). She Thanks are extended to Dr. David Pocknall and a second anonymous led the marine geology team for the 2014 expedition to the Sabrina reviewer for their constructive comments that improved our manuscript. Coast. Shevenell sailed as lead sedimentologist and was a co-propon- This is UTIG Contribution #3282. ent of IODP Expedition 374 to the Ross Sea. SEAN GULICK is a Research Professor at the Disclosure statement University of Texas at Austin in marine geology and geophysics. He has sailed on over twenty-five No potential conflict of interest was reported by the authors. research cruises and been chief or co-chief scientist on fourteen and authored or co-authored over 80 journal articles. He received the Jackson School Funding Outstanding Researcher Award in 2014. His research includes tectonic and climate interactions in high-lati- This work was supported by the National Science Foundation under tude systems such as the East Antarctic margin; geohazards and mar- Grants 1143834, 1143836, 1143837, 1143843, 1313826, 1048343, 131382; gin evolution of subduction and transform plate boundaries; and the and Geological Society of America Graduate Student Research Grant. geologic processes and environmental effects of the Cretaceous- Paleogene Chicxulub meteor impact. He led the seismic acquisition and processing team for the 2014 Nathaniel B. Palmer expedition to the Sabrina Coast. Notes on contributors AMY LEVENTER is a Full Professor of geology at CATHERINE SMITH is currently working as a curator Colgate University. She has been working in with the International Ocean Discovery Program at Antarctica since 1983 and specializes in polar marine Texas A&M University. Catherine was born in New diatoms, but has also worked with planktonic fora- York and attended Hamilton College in Clinton, NY, minifera from the Gulf of . She received her where she received a B.A. in Geosciences. She BS in Aquatic Biology (1979) from Brown University, received her M.S. in Marine Science at the University an MS in Marine Science (1981) from University of of South Florida College of Marine Science in St. South Carolina and a PhD in Geology (1988) from Petersburg, Florida and trained in palynology at the Rice University. After finishing her graduate work, she spent several LSU Center for Excellence in Palynology (CENEX) as a visiting researcher years at Byrd Polar Research Institute Ohio State University, followed by in 2016. While at USF she participated in a cruise to the Sabrina Coast three years at the Limnological Research Center University of Minnesota, aboard the RV/IB Nathaniel B. Palmer where the cores for this project prior to her position at Colgate. PALYNOLOGY 9

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