Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean was conducted to reduce taxonomic uncertainty that will improve our understanding of species’ecology, biogeography and relationship to faunas from other deep-sea regions. Fifteen genera and 40 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images, covering most of known deep-sea species in the central Arctic Ocean. Seven new species are described: Bythoceratina lomonosovensis n. sp., Cytheropteron parahamatum n. sp.,Cytheropteron lanceae n. sp.,Cytheropteron irizukii n. sp., Pedicythere arctica n. sp.,Cluthia whatleyi n. sp.,Krithe hunti n. sp. This study provides a robust taxonomic baseline for application to paleoceanographical reconstruction and biodiversity analyses in this climatically sensitive region.
High-resolution Plate 1
Plate 1: All SEM images. Scale bar represents 1 mm. 1–3 Polycope arcys Joy and Clark 1977. 1, USNM 594082, PS2179, 9–10 cm; RV, lateral view. 2, USNM 594083, PS2186-5, 10–11 cm; LV, lateral view. 3, USNM 594084, PS2202-2, 0–1 cm; LV, lateral view. 4–9 Polycope bispinosa Joy and Clark 1977. 4, USNM 594085, PS2186-5, 10–11 cm; RV, lateral view. 5, USNM 594086, PS2186-5, 10–11 cm; RV, lateral view. 6, USNM 594087, PS2179, 9–10 cm; RV, lateral view. 7, USNM 594088, PS2164-4, 0–1 cm; LV, lateral view. 8, USNM 594089, Geomar 23243-1, 90–91 cm; LV, lateral view. 9, USNM 594090, Geomar 23243-1, 180–181 cm; LV, lateral view.
YasuharaPlate1h.tif
High-resolution Plate 2
Plate 2: All SEM images. Scale bar represents 500 µm. 1–2 Polycope bireticulata Joy and Clark 1977. 1, USNM 594091, PS2177-1, 0–1 cm; RV, lateral view. 2, USNM 594092, PS2177-1, 0–1 cm; RV, lateral view. 3 Polycope reticulata Müller, 1894, USNM 594093, PS2179, 9–10 cm; RV, lateral view. 4–5 Polycope semipunctata Joy and Clark 1977. 4, USNM 594094, PS2186-5, 10–11 cm; RV, lateral view. 5, USNM 594095, PS2200-5, 183 cm; RV, lateral view. 6–9 Polycope moenia Joy and Clark 1977. 6, USNM 594096, PS2202-2, 0–1 cm; LV, lateral view. 7, USNM 594097, PS2202-2, 0–1 cm; RV, lateral view. 8, USNM 594098, PS2200-5, 123 cm; RV, lateral view. 9, USNM 594099, PS2177-1, 0–1 cm; LV, lateral view.
YasuharaPlate2h.tif
High-resolution Plate 3
Plate 3: All SEM images. Scale bar represents 1 mm. 1 Polycope punctata Sars 1869 sensu Joy and Clark (1977), USNM 594100, PS2177-1, 0–1 cm; LV, lateral view. 2–5, 8 Polycope inornata Joy and Clark 1977. 2, USNM 594101, PS2177-1, 0–1 cm; RV, lateral view. 3, USNM 594102, PS2164-4, 0–1 cm; LV, lateral view. 4, USNM 594103, PS2177-1, 0–1 cm; LV, lateral view. 5, USNM 594104, PS2177-1, 0–1 cm; LV, lateral view. 8, USNM 594107, PS2179-3, 17–18 cm; LV, lateral view. 6–7 Polycope sp. 1. 6, USNM 594105, Geomar 23243-1, 55 cm; RV, lateral view. 7, USNM 594106, Geomar 23243-1, 60–61 cm; RV, lateral view. 9–10 Polycope horrida Joy and Clark 1977. 9, USNM 594108, NP26 sta 5, 80–82 cm; RV, lateral view. 10, USNM 594109, NP26 sta 5, 77.5–79 cm; RV, lateral view.
YasuharaPlate3.tif
High-resolution Plate 4
Plate 4 All SEM images and adult specimens. Scale bar represents 1 mm. 1–7 Argilloecia cf. robinwhatleyi Yasuhara, Okahashi and Cronin 2009. 1, USNM 594110, PS2200-5, 178 cm; LV, lateral view. 2, USNM 594111, PS2200-5, 178 cm; RV, lateral view. 3, USNM 594112, PS2200-5, 183 cm; RV, lateral view. 4, USNM 594113, PS1913-5, 0–2 cm; LV, internal view. 5, USNM 594114, PS1913-5, 0–2 cm; RV, internal view. 6, USNM 594115, 10/2, 24–26 cm; LV, lateral view. 7, USNM 594116, 10/2, 24–26 cm; RV, lateral view. 8–9 Argilloecia cf. conoidea Sars 1923. 8, USNM 594117, 10/2, 24–26 cm; LV, lateral view. 9, USNM 594118, 10/2, 24–26 cm; RV, lateral view.
10Australoecia posteroacuta Coles and Whatley, 1989, USNM 594119, 10/2, 24–26 cm; RV, lateral view. 11 Argilloecia sp. 1, USNM 594120, 10/2, 24–26 cm; LV, lateral view.
YasuharaPlate4h.tif
High-resolution Plate 5
Plate 5: All SEM images and adult specimens. Scale bars represent 1 mm. 1–2 Bythoceratina lomonosovensis n. sp. 1, USNM 594121, PS2179-3, 11–12 cm; LV, lateral view. 2, USNM 594122, PS2179-3, 15–16 cm; RV, lateral view. 3–4 Bythoceratina scaberrima (Brady 1886). 3, USNM 594123, PS2202-2, 0–1 cm; LV, lateral view. 4, USNM 594124, PS2185-4, 12–13 cm; RV, lateral view. 5–7 Cytheropteron parahamatum n. sp. 5, USNM 594125, Meteor 23454-2; LV, lateral view. 6, USNM 594126, Meteor 23454-2; RV, lateral view. 7, USNM 594127, PS1913-5, 0–2 cm; RV, lateral view. 8–9 Cytheropteron carolinae Whatley and Coles 1987. 8, USNM 594128, PS1704-3; LV, lateral view. 9, USNM 594129, PS1698-2; RV, lateral view.
YasuharaPlate5.tif
High-resolution Plate 6
Plate 6: All SEM images and adult specimens. Scale bar represents 1 mm. 1–12 Pseudocythere caudata Sars 1866. 1, USNM 594130, PS2186-5, 10–11 cm; LV, lateral view. 2, USNM 594131, PS2189-1, 0–1 cm; RV, lateral view. 3, USNM 594132, PS2189-1, 0–1 cm; LV, lateral view. 4, USNM 594133, 10/2, 4–6 cm; LV, lateral view. 5, USNM 594134, PS2189-1, 0–1 cm; RV, lateral view. 6, USNM 594135, PS2186-5, 10–11 cm; LV, lateral view. 7, USNM 594136, Geomar 23243-1, 100–101 cm; LV, lateral view. 8, USNM 594137, 10/2, 4–6 cm; RV, lateral view. 9, USNM 594138, 10/2, 4–6 cm; LV, lateral view. 10, USNM 594139, Geomar 23243-1, 100–101 cm; RV, lateral view. 11, USNM 594140, 10/2, 4–6 cm; LV, lateral view. 12, USNM 594141, 10/2, 4–6 cm; RV, lateral view.
YasuharaPlate6.tif
High-resolution Plate 7
Plate 7: All SEM images and adult specimens. Scale bar represents 1 mm. 1–3 Cytheropteron higashikawai Ishizaki 1981. 1, USNM 594142, PS1893-1; LV, lateral view. 2, USNM 594143, PS1893-1; RV, lateral view. 3, USNM 594144, Geomar 23243-1, 64 cm; LV, lateral view. 4–7 Cytheropteron sedovi Schneider, 1962. 4, USNM 594145, PS2195-4, 0–1 cm; RV, lateral view. 5, USNM 594146, Pl-91-AR-BC02; LV, lateral view. 6, USNM 594147, PS2179-3, 9–10 cm; RV, lateral view. 7, USNM 594148, PS2179-3, 9–10 cm; LV, lateral view. 8 Cytheropteron lanceae n. sp., USNM 594149, NP-26/32, 2.5–5.0 cm; RV, lateral view.
YasuharaPlate7.tif
High-resolution Plate 8
Plate 8: All SEM images and adult specimens. Scale bar represents 1 mm. 1–8 Cytheropteron perlaria Hao 1988. 1, USNM 594150, PS1905-1; LV, lateral view. 2, USNM 594151, PS1698-2; RV, lateral view. 3, USNM 594152, NP-19/18; RV, lateral view. 4, USNM 594153, NP-19/18; RV, lateral view. 5, USNM 594154, NP-19/19; LV, lateral view. 6, USNM 594155, NP-19/19; RV, lateral view. 7, USNM 594156, NP-19/19; LV, lateral view. 8, USNM 594157, NP-19/19; RV, lateral view.
YasuharaPlate8.tif
High-resolution Plate 9
Plate 9: All SEM images and adult specimens. Scale bar represents 1 mm. 1–4 Cytheropteron groenlandicum Whatley and Eynon 1996. 1, USNM 594158, PS1905-1; RV, lateral view. 2, USNM 594159, PS1698-2; LV, lateral view. 3, USNM 594160, NP-19/19; LV, lateral view. 4, USNM 594161, NP-19/19; RV, lateral view. 5–6 Cytheropteron irizukii n. sp. 5, USNM 594162, PS2189-1, 0–1 cm; LV, lateral view. 6, USNM 594163, PS2189-1, 0–1 cm; RV, lateral view. 7–9 Cytheropteron scoresbyi Whatley and Eynon 1996. 7, USNM 594164, Pl-91-AR-BC02; LV, lateral view. 8, USNM 594165, Meteor 23454-2; RV, lateral view. 9, USNM 594166, Meteor 23454-2; LV, lateral view.
YasuharaPlate9.tif
High-resolution Plate 10
Plate 10: All SEM images and adult specimens. Scale bar represents 1 mm.1, 3 Cytheropteron aielloi Yasuhara, Okahashi and Cronin 2009. 1, USNM 594167, PS2189-1, 0–1 cm; LV, lateral view. 3, USNM 594169, PS1913-5, 0–2 cm; RV, lateral view. 2 Cytheropteron scoresbyi Whatley and Eynon 1996, USNM 594168, Meteor 23453-1; RV, lateral view. 4–5 Cytheropteron carolinae Whatley and Coles 1987. 4, USNM 594170, Meteor 23453-1; LV, lateral view. 5, USNM 594171, Meteor 23453-1; RV, lateral view. 6–9 Cytheropteron pseudoinflatum Whatley and Eynon 1996. 6, USNM 594172, PS2200-5, 123 cm; LV, lateral view. 7, USNM 594173, Meteor 23453-1; LV, lateral view. 8, USNM 594174, PS2200-5, 123 cm; RV, lateral view. 9, USNM 594175, Meteor 23453-1; RV, lateral view.
YasuharaPlate10.tif
High-resolution Plate 11
Plate 11: All SEM images and adult specimens. Scale bar represents 1 mm. 1–2 Cytheropteron pseudoinflatum Whatley and Eynon 1996. 1, USNM 594176, Meteor 23455-2; LV, lateral view. 2, USNM 594177, Meteor 23455-2; RV, lateral view.
3–6 Eucytherura delineata, Whatley and Eynon 1996. 3, USNM 594178, PS2202-2, 0–1 cm; LV, lateral view. 4, USNM 594179, PS2202-2, 0–1 cm; RV, lateral view. 5, USNM 594180, NP-19/20; LV, lateral view. 6, USNM 594181, NP-19/20; RV, lateral view. 7–10 Pedicythere neofluitans, Joy and Clark 1977. 7, USNM 594182, PS2186-5, 0–1 cm; LV, lateral view. 8, USNM 594183, PS2189-1, 0–1 cm; LV, lateral view. 9, USNM 594184, PS2189-1, 0–1 cm; LV, lateral view. 10, USNM 594185, PS2202-2, 0–1 cm; RV, lateral view.
YasuharaPlate11.tif
High-resolution Fig. 12
Plate 12: All SEM images and adult specimens. Scale bars represent 0.5 mm. 1–2 Pedicythere arctica n. sp. 1, USNM 594186, PS2202-2, 0–1 cm; RV, lateral view. 2, USNM 594187, NP-19/19; LV, lateral view. 3 Eucythere argus (Sars 1866), USNM 594188, NP26 sta 5, 78–80 cm; LV, lateral view. 4–8 Cluthia whatleyi n. sp. 4, USNM 594189, NP-19/20; LV, lateral view. 5, USNM 594190, NP-19/20; RV, lateral view. 6, USNM 594191, PS2202-2, 0–1 cm; RV, lateral view. 7, USNM 594192, NP-19/10; RV, internal view. 8, USNM 594193, NP-19/10; LV, internal view.
YasuharaPlate12.tif
High-resolution Plate 13
Plate 13: All SEM images and adult specimens. Scale bar represents 1 mm. 1–11 Krithe hunti n. sp. 1, USNM 594194, Meteor 23454-2; LV, lateral view. 2, USNM 594195, Meteor 23454-2; RV, lateral view. 3, USNM 594196, PS1698-2; LV, lateral view. 4, USNM 594197, PS1707-1; RV, lateral view. 5, USNM 594198, NP-26/32, 2.5–5.0 cm; LV, lateral view. 6, USNM 594199, Meteor 23454-2; RV, lateral view. 7, USNM 594200, NP-26/32, 2.5–5.0 cm; LV, lateral view. 8, USNM 594201, NP-26/32, 8.5–9.5 cm; RV, lateral view. 9, USNM 594202, Geomar 23243-1, 63 cm; RV, lateral view. 10, USNM 594203, NP-26/32, 2.5–5.0 cm; LV, lateral view. 11, USNM 594204, NP-26/32, 78–80 cm; RV, lateral view.
YasuharaPlate13.tif
High-resolution Plate 14
Plate 14: All SEM images. Scale bar represents 1 mm. 1–11 Krithe hunti n. sp. 1, USNM 594205, PS2163-2, 0–1 cm; LV, adult, lateral view. 2, USNM 594206, NP-26/32, 2.5–5.0 cm; LV, A-1, lateral view. 3, USNM 594207, NP-26/32, 2.5–5.0 cm; RV, A-1, lateral view. 4, USNM 594208, NP-26/32, 2.5–5.0 cm; LV, A-2, lateral view. 5, USNM 594209, NP-26/32, 2.5–5.0 cm; RV, A-2, lateral view. 6, USNM 594210, NP-26/32, 2.5–5.0 cm; LV, A-3, lateral view. 7, USNM 594211, NP-26/32, 2.5–5.0 cm; RV, A-3, lateral view. 8, USNM 594212, NP-26/32, 2.5–5.0 cm; LV, A-4, lateral view. 9, USNM 594213, NP-26/32, 2.5–5.0 cm; RV, A-4, lateral view. 10, USNM 594214, NP-26/32, 2.5–5.0 cm; LV, A-5, lateral view. 11, USNM 594215, NP-26/32, 2.5–5.0 cm; RV, A-5, lateral view. 12–25 Krithe minima Coles, Whatley and Moguilevsky 1994. 12, USNM 594216, PS1913-5, 0–2 cm; RV, A-3, lateral view. 13, USNM 594217, PS1913-5, 0–2 cm; LV, A-2, lateral view. 14, USNM 594218, PS1913-5, 0–2 cm; RV, A-2, lateral view. 15, USNM 594219, PS1913-5, 0–2 cm; LV, A-1, lateral view. 16, USNM 594220, PS1913-5, 0–2 cm; RV, A-1, lateral view. 17, USNM 594221, PS1913-5, 0–2 cm; LV, adult, lateral view. 18, USNM 594222, Meteor 23455-2; RV, adult, lateral view. 19, USNM 594223, PS2212-6, 6–7 cm; LV, adult, lateral view. 20, USNM 594224, PS2179-3, 9–10 cm; RV, adult, lateral view. 21, USNM 594225, Geomar 23243-1, 100–101 cm; LV, adult, lateral view. 22, USNM 594226, Meteor 23455-2; RV, adult, lateral view. 23, USNM 594227, Geomar 23243-1, 180–181 cm; LV, adult, lateral view. 24, USNM 594228, PS2212-6, 6–7 cm; LV, adult, lateral view. 25, USNM 594229, PS2179-3, 9–10 cm; RV, adult, lateral view.
YasuharaPlate14.tif
High-resolution Plate 15
Plate 15: All SEM images. Scale bars represent 0.5 mm (except scale bar for 5b that represents 50 µm). 1–3 Acetabulastoma arcticum Schornikov 1970. 1, USNM 594230, PS2189-1, 0–1 cm; LV, lateral view. 2, USNM 594231, PS2164-4, 0–1 cm; RV, lateral view. 3, USNM 594232, PS2200-5, 183 cm; LV, lateral view. 4 Paradoxostomatid sp. 1, USNM 594233, 10/2, 24–26 cm; RV, lateral view.
5–6 Paracytherois chukchiensis Joy and Clark 1977. 5a–b, USNM 594234, PS2200-5, 178 cm; RV, adult, lateral view (5a, whole view; 5b, closeup view). 6, USNM 594235, PS2200-5, 178 cm; LV, adult, lateral view. 7–11 Microcythere medistriata (Joy and Clark 1977). 7, USNM 594236, PS2179, 9–10 cm; RV, adult, lateral view. 8, USNM 594237, PS2200-5, 183 cm; LV, adult, lateral view. 9, USNM 594238, NP-19/9; RV, adult, lateral view. 10, USNM 594239, NP-19/10; LV, adult, lateral view. 11, USNM 594240, NP-19/10; LV, adult, internal view.
YasuharaPlate15.tif
High-resolution Plate 16
Plate 16: All SEM images and adult specimens. Scale bars represent 0.5 mm. 1–2 Microcythere medistriata (Joy and Clark 1977). 1, USNM 594241, NP-19/10; RV, internal view. 2, USNM 594242, NP-19/18; LV, internal view. 3–10 Henryhowella asperrima (Reuss 1850). 3, USNM 594243, Meteor 23456-6; LV, lateral view. 4, USNM 594244, Meteor 23456-6; RV, lateral view. 5, USNM 594245, PS2184-3, 1–2 cm; LV, lateral view. 6, USNM 594246, Meteor 23457-3; RV, lateral view. 7, USNM 594247, Geomar 23243-1, 48 cm; LV, lateral view. 8, USNM 594248, Meteor 23457-3; RV, lateral view. 9, USNM 594249, Geomar 23243-1, 210–211 cm; LV, lateral view. 10, USNM 594250, Geomar 23243-1, 100–101 cm; RV, lateral view.
YasuharaPlate16.tif
High-resolution Text-fig. 2
Text-fig. 2 The SEM images of Cytheropteron sedovi Schneider, 1962 and Cytheropteron lanceae n. sp. 1–4, Cytheropteron sedovi. 1, USNM 594251, AF07-31, 37–41 cm; LV, lateral view. 2, USNM 594252, AF07-31, 150–154 cm; RV, lateral view. 3, USNM 594253, AF07-31, 7–11 cm; LV, lateral view. 4, USNM 594254, AF07-31, 0–4 cm; LV, lateral view. 5–6, Cytheropteron lanceae. 5, USNM 594255, AF07-31, 330–333 cm; RV, lateral view. 6, USNM 594256, AF07-31, 37–41 cm; LV, lateral view. Scale bar represents 1 mm.
YasuharaText-Fig2.tif
High-resolution Text-fig. 3
Text-fig. 3 The SEM image of topotype specimen (RV) of Cytheropteron vespertilio (Reuss 1850) from the former clay pit of Baden-Sooss in Lower Austria (stratotype of the Badenian), Vienna Basin, Miocene, Lower Badenian, Upper Lagenidae Zone (Rögl et al. 2008). Courtesy of Dr. Irene Zorn. Scale bar represents 0.5 mm.
Yasuhara_Text-fig3-360.tif
Appendix 1
Appendix 1. Detailed information of the specimens used for the present study. USNM: accession number. T: type (P: paratype. H: holotype). V: valve (L: left. R: right). A: adult. A-1: last juvenile instar (adult minus one). F: female. M: male.
Yasuhara_app1-USNM-fin.xls
Table 1
Table 1. Sample list. Lat: latitude. Long: longitude. WD: water depth (m).
Yasuhara_Tab1.xls
Table 2
Table 2. Size of selected ostracod specimens. USNM: accession number. T: type (P: paratype. H: holotype). V: valve (L: left. R: right). A: adult. F: female. M: male. L: Length (mm). H: Height (mm).
Yasuhara_Tab2-USNM.xls