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Quaternary equatorial Atlantic deep-sea ostracodes: evidence for a distinct tropical fauna in the deep sea

Part of:Memoirs

Published online by Cambridge University Press:  11 August 2021

Moriaki Yasuhara*
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China
Hisayo Okahashi
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China
Huai-Hsuan May Huang
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA
Yuanyuan Hong
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China
Hokuto Iwatani
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China Division of Earth Science, The Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yoshida 1677-1, Yamaguchi 753-8511, Japan
Rachel Wai Ching Chu
Affiliation:
School of Biological Sciences, Division for Ecology and Biodiversity, Swire Institute of Marine Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong SAR, China
Gene Hunt
Affiliation:
Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA
*
*Corresponding author

Abstract

Low-latitude, deep-sea faunas remain poorly understood and described. Here, we systematically describe Quaternary deep-sea ostracodes from the Ocean Drilling Program (ODP) Site 925 (Ceara Rise; 4°12.2'N, 43°29.3′W; 3040 m water depth) in the equatorial Atlantic Ocean. Twenty-six genera and 52 species were examined and illustrated with high-resolution scanning electron microscopy images. Six new species are described herein: Pseudocythere spinae, Hemiparacytheridea zarikiani, Pedicythere canis, Xylocythere denticulata, Paracytherois obtusa, and Poseidonamicus sculptus. The results show that deep-sea ostracodes have a tropical faunal element that is distinctive from higher latitude ostracodes, and that is globally distributed in low latitudes. This tropical faunal component is possibly a Tethyan legacy of a fauna that was widely distributed in tropical and extratropical latitudes in deep waters during greenhouse conditions in the Cretaceous and early Cenozoic. Global cooling thereafter shrank its distribution, limiting it to tropical latitudes, perhaps with the relatively warm uppermost bathyal area acting as the source or refuge of this faunal component. Because similar present-day biogeographic patterns (i.e., presence and wide distribution of tropical deep-sea fauna) are known in other deep-sea benthic groups, this scenario might be applicable to the deep-sea benthos more broadly.

UUID: http://zoobank.org/552d4cb2-c0db-463a-ae3f-b2efcc0985df.

Information

Type
Memoir
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of The Paleontological Society
Figure 0

Figure 1.Locality map indicating ODP Site 925 (4°12.2′N, 43°29.3′W). This map was generated with R package “marmap” by using the NOAA's ETOPO1 bathymetric data (Pante and Simon-Bouhet, 2013).

Figure 1

Figure 2.Scanning electron microscope images of Polycope, Bythocypris, and Zabythocypris species. (1–9) Polycope orbicularis s.l. Sars, 1866; (1) USNM PAL 771616 (ODP925202), RV; (2) USNM PAL 771617 (ODP925203), LV; (3) USNM PAL 771618 (ODP925207), RV; (4) USNM PAL 771619 (ODP925208), LV; (5) USNM PAL 771620 (ODP925209), LV; (6) USNM PAL 771621 (ODP925211), LV; (7) USNM PAL 771622 (ODP925204), LV; (8) USNM PAL 771623 (ODP925205), RV; (9) USNM PAL 771624 (ODP925210), RV. (10) Polycope vasfiensis Sissingh, 1972, USNM PAL 771625 (ODP925206), LV. (11) Bythocypris weddellensis Brandão, 2008, USNM PAL 771626 (ODP925013), juvenile? RV. (12, 13) Zabythocypris ancipita Maddocks, 1969; (12) USNM PAL 771627 (ODP925011), adult? RV; (13) USNM PAL 771628 (ODP925012), juvenile LV. All lateral views. Scale bar = 1 mm.

Figure 2

Figure 3.Scanning electron microscope images of Zabythocypris, Macrocypris, Aratrocypris, Argilloecia, and Propontocypris species. (1–3) Zabythocypris heterodoxa (Chapman, 1910); (1) USNM PAL 771629 (ODP925257), A-1 juvenile LV; (2) USNM PAL 771630 (ODP925258), adult LV; (3) USNM PAL 771631 (ODP925259), adult RV. (4) Macrocypris miranda s.l. Maddocks, 1990, USNM PAL 771632 (ODP925212), adult? LV. (5, 6) Aratrocypris sp. 1; (5) USNM PAL 771633 (ODP925003), juvenile? LV; (6) USNM PAL 771634 (ODP925002), juvenile? RV. (7, 8) Argilloecia acuminata Müller, 1894; (7) USNM PAL 771635 (ODP925004), adult LV; (8) USNM PAL 771636 (ODP925005), adult? RV. (9–11) Argilloecia labri Yasuhara and Okahashi, 2015; (9) USNM PAL 771637 (ODP925006), adult? RV; (10) USNM PAL 771638 (ODP925007), adult? LV; (11) USNM PAL 771639 (ODP925159), adult RV. (12, 13) Argilloecia sp. 1; (12) USNM PAL 771640 (ODP925008), adult? LV; (13) USNM PAL 771641 (ODP925009), adult? RV. (14) Propontocypris trigonella s.l. (Sars, 1866), USNM PAL 771642 (ODP925218), juvenile LV. All lateral views, except (11), internal view. Scale bars = 1 mm.

Figure 3

Figure 4.Scanning electron microscope images of Pseudocythere species. (1) Pseudocythere fuegiensis Brady, 1880, USNM PAL 771643 (ODP925223), adult RV. (2–14) Pseudocythere caudata Sars, 1866; (2) USNM PAL 771644 (ODP925224), adult LV; (3) USNM PAL 771645 (ODP925225), adult RV; (4) USNM PAL 771646 (ODP925233), adult LV; (5) USNM PAL 771647 (ODP925234), adult RV; (6) USNM PAL 771648 (ODP925227), adult LV; (7) USNM PAL 771649 (ODP925232), adult RV; (8) USNM PAL 771650 (ODP925235), adult LV; (9) USNM PAL 771651 (ODP925236), adult RV; (10) USNM PAL 771652 (ODP925238), adult LV; (11) USNM PAL 771653 (ODP925239), adult LV; (12) USNM PAL 771654 (ODP925241), adult RV; (13) USNM PAL 771655 (ODP925237), adult RV; (14) USNM PAL 771656 (ODP925240), adult RV. (15) Pseudocythere sp. 1, USNM PAL 771657 (ODP925226), adult RV. (16–19) Pseudocythere spinae n. sp.; (16) USNM PAL 771658 (ODP925229), holotype, adult RV; (17) USNM PAL 771659 (ODP925228), paratype, adult LV; (18) USNM PAL 771660 (ODP925231), paratype, adult RV; (19) USNM PAL 771661 (ODP925230), paratype, adult LV. (1–3, 6–8, 10–13, 15–17) lateral views; (4, 5, 9, 14, 18, 19) internal views. Scale bars = 1 mm.

Figure 4

Figure 5.Scanning electron microscope images of Ruggieriella, Aversovalva, and Cytheropteron species. (1) Ruggieriella mcmanusi Yasuhara, Okahashi, and Cronin, 2009c, USNM PAL 771662 (ODP925244), adult RV. (2) Aversovalva atlantica Whatley and Coles, 1987, USNM PAL 771663 (ODP925010), juvenile LV. (3–5) Cytheropteron carolinae Whatley and Coles, 1987; (3) USNM PAL 771664 (ODP925014), adult LV; (4) USNM PAL 771665 (ODP925015), adult LV; (5) USNM PAL 771666 (ODP925016), adult RV. (6–8) Cytheropteron omega Aiello, Barra, and Bonaduce, 1996; (6) USNM PAL 771667 (ODP925018), adult LV; (7) USNM PAL 771668 (ODP925019), adult LV; (8) USNM PAL 771669 (ODP925030), adult RV. (9, 10) Cytheropteron porterae Whatley and Coles, 1987; (9) USNM PAL 771670 (ODP925020), juvenile? RV; (10) USNM PAL 771671 (ODP925029), adult RV. (11–13) Cytheropteron demenocali Yasuhara, Okahashi, and Cronin, 2009c; (11) USNM PAL 771672 (ODP925021), adult LV; (12) USNM PAL 771673 (ODP925242), adult LV; (13) USNM PAL 771674 (ODP925243), adult? RV. All lateral views, except (4), internal view. Scale bar = 1 mm.

Figure 5

Figure 6.Scanning electron microscope images of Cytheropteron species. (1–4) Cytheropteron cf. C. lineoporosa Whatley and Coles, 1987; (1) USNM PAL 771675 (ODP925023), adult LV; (2) USNM PAL 771676 (ODP925024), adult RV; (3) USNM PAL 771677 (ODP925025), adult LV; (4) USNM PAL 771678 (ODP925026), adult RV. (5–7) Cytheropteron lineoporosa Whatley and Coles, 1987; (5) USNM PAL 771679 (ODP925027), adult RV; (6) USNM PAL 771680 (ODP925028), adult LV; (7) USNM PAL 771681 (ODP925017), adult RV. (8) Cytheropteron sp. 1, USNM PAL 771682 (ODP925022), adult RV. All lateral views, except (3, 4), internal views. Scale bar = 1 mm.

Figure 6

Figure 7.Scanning electron microscope images of Eucytherura and Hemiparacytheridea species. (1–3) Eucytherura spinicorona Yasuhara, Okahashi, and Cronin, 2009c; (1) USNM PAL 771683 (ODP925033), adult? LV; (2) USNM PAL 771684 (ODP925034), adult? RV; (3) USNM PAL 771685 (ODP925035), adult? LV. (4–6) Eucytherura calabra (Colalongo and Pasini, 1980); (4) USNM PAL 771686 (ODP925036), adult RV; (5) USNM PAL 771687 (ODP925037), adult LV; (6) USNM PAL 771688 (ODP925038), adult RV. (7–10) Eucytherura downingae (Coles and Whatley, 1989); (7) USNM PAL 771689 (ODP925039), adult LV; (8) USNM PAL 771690 (ODP925042), adult LV; (9) USNM PAL 771691 (ODP925040), adult RV; (10) USNM PAL 771692 (ODP925041), adult RV. (11–14) Hemiparacytheridea zarikiani n. sp.; (11) USNM PAL 771693 (ODP925044), holotype, adult LV; (12) USNM PAL 771694 (ODP925048), paratype, adult RV; (13) USNM PAL 771695 (ODP925049), paratype, adult LV; (14) USNM PAL 771696 (ODP925050), paratype, adult RV. (15, 16) Eucytherura multituberculata Ayress et al., 1995; (15) USNM PAL 771697 (ODP925046), adult RV; (16) USNM PAL 771698 (ODP925043), adult LV. (1, 2, 4, 5, 7, 9, 11, 12, 15, 16) lateral views; (3, 6, 8, 10, 13, 14) internal views. Scale bar = 1 mm.

Figure 7

Figure 8.Scanning electron microscope images of Pedicythere species. (1, 2) Pedicythere atroposopetasi Yasuhara, Okahashi, and Cronin, 2009c, USNM PAL 771699 (ODP925198), adult LV. (3–16) Pedicythere kennettopetasi Yasuhara, Okahashi, and Cronin, 2009c; (3, 4) USNM PAL 771700 (ODP925183), adult LV; (5, 6) USNM PAL 771701 (ODP925187), adult LV; (7, 8) USNM PAL 771702 (ODP925188), adult LV; (9, 10) USNM PAL 771703 (ODP925192), adult RV; (11, 12) USNM PAL 771704 (ODP925193), adult RV; (13, 14) USNM PAL 771705 (ODP925196), adult LV; (15, 16) USNM PAL 771706 (ODP925200), adult LV. (17–20) Pedicythere cf. P. kennettopetasi Yasuhara, Okahashi, and Cronin, 2009c; (17, 18) USNM PAL 771707 (ODP925191), adult LV; (19) USNM PAL 771708 (ODP925185), adult LV; (20) USNM PAL 771709 (ODP925184), adult LV. (1–6, 9, 10, 13–20) lateral views; (7, 8, 11, 12) internal views; (2, 4, 6, 7, 10, 11, 14, 16, 18) oblique views. Scale bar = 1 mm.

Figure 8

Figure 9.Scanning electron microscope images of Pedicythere species. (1–4) Pedicythere cf. P. kennettopetasi Yasuhara, Okahashi, and Cronin, 2009c; (1, 2) USNM PAL 771710 (ODP925194), adult LV; (3, 4) USNM PAL 771711 (ODP925201), adult RV. (5–8) Pedicythere canis n. sp.; (5, 6) USNM PAL 771712 (ODP925199), holotype, adult RV; (7, 8) USNM PAL 771713 (ODP925195), paratype, adult LV. (9–11) Pedicythere sp. 1; (9, 10) USNM PAL 771714 (ODP925189), adult LV; (11) USNM PAL 771715 (ODP925190), adult LV. (12, 13) Pedicythere lachesisopetasi Yasuhara, Okahashi, and Cronin, 2009c, USNM PAL 771716 (ODP925186), adult LV. (14, 15) Pedicythere sp. 2, USNM PAL 771717 (ODP925197), adult RV. (3–10, 12–15) lateral views; (1, 2, 11) internal views; (1, 4, 6, 8, 10, 11, 13, 15) oblique views. Scale bar = 1 mm.

Figure 9

Figure 10.Scanning electron microscope images of Rimacytheropteron, Semicytherura, Eucythere, and Xylocythere species. (1) Rimacytheropteron longipunctatum (Breman, 1976), USNM PAL 771718 (ODP925245), adult RV. (2–5) Semicytherura pulchra (Coles and Whatley, 1989); (2, 3) USNM PAL 771719 (ODP925045), adult LV; (4, 5) USNM PAL 771720 (ODP925047), adult LV. (6–9) Semicytherura coeca Ciampo, 1986; (6, 7) USNM PAL 771721 (ODP925255), adult LV; (8, 9) USNM PAL 771722 (ODP925256), adult RV. (10, 11) Eucythere pubera Bonaduce, Ciampo, and Masoli, 1976; (10) USNM PAL 771723 (ODP925031), juvenile? LV; (11) USNM PAL 771724 (ODP925032), juvenile RV. (12–15) Xylocythere denticulata n. sp.; (12) USNM PAL 771725 (ODP925251), holotype, adult LV; (13) USNM PAL 771726 (ODP925252), paratype, adult LV; (14) USNM PAL 771727 (ODP925253), paratype, adult RV; (15) USNM PAL 771728 (ODP925254), paratype, adult LV. (1, 2, 4, 7, 8, 10–14) lateral views; (3, 5, 6, 9, 15) inner views. Scale bars = 1 mm.

Figure 10

Figure 11.Scanning electron microscope images of Chejudocythere and Paracytherois species. (1, 2) Chejudocythere subtriangulata Hao in Ruan and Hao, 1988, USNM PAL 771729 (ODP925260), adult LV. (3–20) Paracytherois bondi Yasuhara, Okahashi, and Cronin, 2009c; (3) USNM PAL 771730 (ODP925151), adult LV; (4) USNM PAL 771731 (ODP925152), adult RV; (5, 6) USNM PAL 771732 (ODP925154), adult RV; (7) USNM PAL 771733 (ODP925153), adult LV; (8) USNM PAL 771734 (ODP925155), adult LV; (9, 10) USNM PAL 771735 (ODP925156), adult RV; (11) USNM PAL 771736 (ODP925157), adult LV; (12) USNM PAL 771737 (ODP925158), adult RV; (13, 14) USNM PAL 771738 (ODP925164), adult LV; (15) USNM PAL 771739 (ODP925165), adult RV; (16) USNM PAL 771740 (ODP925166), adult LV; (17) USNM PAL 771741 (ODP925167), adult RV; (18) USNM PAL 771742 (ODP925168), adult LV; (19, 20) USNM PAL 771743 (ODP925169), adult RV. (1–7, 11–17) lateral views; (8–10, 18–20) internal views; (2) closeup of a sieve-type pore; (5, 14) closeup of fine striations; (9, 19) closeup of subcentral muscle scars. Scale bars of closeup views (2, 5, 9, 14, 19) = 10 μm; scale bars for the other images (1, 3, 4, 6–8, 10–13, 15–18, 20) = 0.5 mm.

Figure 11

Figure 12.Scanning electron microscope images of Paracytherois species. (1–3) Paracytherois bondi Yasuhara, Okahashi, and Cronin, 2009c; (1) USNM PAL 771744 (ODP925171), adult RV; (2) USNM PAL 771745 (ODP925172), adult LV; (3) USNM PAL 771746 (ODP925173), adult RV. (4–12) Paracytherois obtusa n. sp.; (4) USNM PAL 771747 (ODP925170), paratype, adult LV; (5, 6) USNM PAL 771748 (ODP925174), holotype, adult LV; (7) USNM PAL 771749 (ODP925175), paratype, adult RV; (8) USNM PAL 771750 (ODP925176), paratype, adult RV; (9) USNM PAL 771751 (ODP925177), paratype, adult LV; (10, 11) USNM PAL 771752 (ODP925178), paratype, adult RV; (12) USNM PAL 771753 (ODP925179), paratype, adult LV. (13–16) Paracytherois productum (Brady and Norman, 1889); (13) USNM PAL 771754 (ODP925180), adult LV; (14) USNM PAL 771755 (ODP925181), adult RV; (15, 16) USNM PAL 771756 (ODP925182), adult LV. (1–8, 12–14) lateral views; (9–11, 15, 16) internal views; (6) closeup of fine striations; (11, 16) closeup of subcentral muscle scars. Scale bars of closeup views (6, 11, 16) = 10 μm; scale bars for the other images (1–5, 7–10, 12–15) = 1 mm.

Figure 12

Figure 13.Scanning electron microscope images of Poseidonamicus species. (1–6) Poseidonamicus sculptus n. sp.; (1) USNM PAL 771757 (ODP925213), holotype, adult female LV; (2) USNM PAL 771758 (ODP925215), paratype, adult male RV; (3, 4) USNM PAL 771759 (ODP925216), paratype, adult female LV; (5, 6) USNM PAL 771760 (ODP925217), paratype, adult female RV. (7) Poseidonamicus cf. P. sculptus n. sp., USNM PAL 771761 (ODP925214), adult male LV. (8, 9) Poseidonamicus pintoi Benson, 1972 from Albatross Station 2763, South Atlantic Ocean (24.28°S, 42.8°W); (8) USNM PAL 527091 (SI55-01), adult female LV; (9) USNM PAL 771762 (SI55-19), adult male RV. (1, 2, 4, 6–9) lateral views; (3, 5) internal views. Scale bar = 1 mm.

Figure 13

Figure 14.Length-to-height ratio for adults of Poseidonamicus pintoi and Poseidonamicus sculptus n. sp. Boxplots are for Poseidonamicus pintoi from its type locality (white) and a large sample of Poseidonamicus sculptus n. sp. from Chain Core 82-24 (gray) from the North Atlantic Ocean (41.7°N, 32.9°W). Males and females are shown separately. Sexes were identified using the procedure of Hunt et al. (2017); numbers inside boxes indicate sample sizes. Black dots indicate measurements from the four figured individuals from ODP 925 (Fig. 13.1, 13.2, 13.4, and 13.6).

Figure 14

Figure 15.Scanning electron microscope images of Pterygocythere, Xestoleberis, and Abyssocythere species. (1–4) Pterygocythere nobilis (Jellinek, Swanson, and Mazzini, 2006); (1) USNM PAL 771763 (ODP925219), adult RV; (2) USNM PAL 771764 (ODP925220), adult RV; (3) USNM PAL 771765 (ODP925221), adult LV; (4) USNM PAL 771766 (ODP925222), A-1 juvenile? LV. (5–9) Xestoleberis oppoae Yasuhara, Okahashi, and Cronin, 2009c; (5) USNM PAL 771767 (ODP925246), juvenile? RV; (6) USNM PAL 771768 (ODP925248), adult RV; (7) USNM PAL 771769 (ODP925247), adult LV; (8) USNM PAL 771770 (ODP925249), adult LV; (9) USNM PAL 771771 (ODP925250), adult RV. (10) Abyssocythere atlantica Benson, 1971, USNM PAL 771772 (ODP925001), juvenile RV. (2–7, 10) lateral views; (1, 8, 9) internal views. Scale bars = 1 mm.

Figure 15

Figure 16.Scanning electron microscope images of Henryhowella asperrima (Reuss, 1850). (1) USNM PAL 771773 (ODP925051), adult LV; (2) USNM PAL 771774 (ODP925052), adult RV; (3) USNM PAL 771775 (ODP925053), adult LV; (4) USNM PAL 771776 (ODP925054), adult RV; (5) USNM PAL 771777 (ODP925055), adult LV; (6) USNM PAL 771778 (ODP925056), adult LV; (7) USNM PAL 771779 (ODP925058), adult LV; (8) USNM PAL 771780 (ODP925057), adult RV. (1–5, 7) lateral views; (6, 8) internal views. Scale bar = 1 mm.

Figure 16

Figure 17.Scanning electron microscope images of Legitimocythere acanthoderma (Brady, 1880). (1) USNM PAL 771781 (ODP925150), adult LV; (2) USNM PAL 771782 (ODP925160), adult LV; (3) USNM PAL 771783 (ODP925161), adult RV; (4) USNM PAL 771784 (ODP925162), adult LV; (5) USNM PAL 771785 (ODP925163), adult RV. (1–3) lateral views; (4, 5) internal views. Scale bar = 1 mm.

Figure 17

Figure 18.Pie chart showing the faunal composition of the ODP 925 ostracodes. All samples studied are lumped to calculate relative abundances of genera. Zabythocypris, Aratrocypris, Hemiparacytheridea, Chejudocythere, and Semicytherura are not abundant (<1% in total, among 5008 ostracode specimens that we picked and counted) and not among the top eight genera shown in the pie chart.

Figure 18

Figure 19.Deep-sea benthic biogeographic provinces. Top panel for lower bathyal (BY) provinces (801–3500 m) and bottom panel for abyssal (AB) provinces (3501–6500 m). From Watling et al. (2013). ODP Site 925 is indicated.