New occurrences of Fortipecten hallae (Dall, 1921) (Mollusca, Bivalvia) in the Pliocene of the North Pacific

Palaeogeography, Palaeoclimatology, Palaeoecology 223 (2005) 162 – 171 www.elsevier.com/locate/palaeo

New occurrences of Fortipecten hallae (Dall, 1921) (Mollusca, Bivalvia) in the Pliocene of the North Pacific Konstantin B. Barinova, Anton E. Oleinikb,T, Louie Marincovich Jr.c a

Russian Academy of Sciences, Geological Institute, Pyzhevsky per. 7, Moscow, Russia 109017 b Florida Atlantic University, Department of Geography and Geology, United States c Department of Invertebrate Zoology and Geology, California Academy of Sciences, 875 Howard Street, San Francisco, CA 94103, United States Received 25 August 2004; received in revised form 22 March 2005; accepted 31 March 2005

Abstract The large North Pacific bivalve mollusk index-fossil Fortipecten hallae (Dall, 1921) is present in a well-dated stratigraphic section of the Milky River Formation, Alaska Peninsula, southwestern Alaska. Co-occurring marine diatoms belong to the upper part of the subzone B of the Neodenticula kamtschatica diatom zone of the North Pacific diatom chronostratigraphy, with an age range of 4.8–5.1 Ma (early Pliocene). Based on coeval occurrences in northeastern Kamchatka, Russia, and synchronous changes in the two molluscan assemblages, F. hallae is a useful indicator of early Pliocene climatic warming along the highlatitude North Pacific margin. D 2005 Elsevier B.V. All rights reserved. Keywords: Neogene; North Pacific; Stratigraphy; Fortipecten; Early Pliocene

1. Introduction The pectinid bivalve mollusk Fortipecten (Yabe and Hatai, 1940), with a thick shell resistant to abrasion and breakage, and its wide geographic distribution (northern Japan to Alaska) is a wellrecognized Neogene shallow-marine index fossil in the North Pacific. Eight species of Fortipecten are T Corresponding author. E-mail addresses: [email protected] (A.E. Oleinik), [email protected] (K.B. Barinov), [email protected] (L. Marincovich). 0031-0182/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2005.04.003

known in the North Pacific (Table 1) (Kafanov, 1986; Barinov, 2001; Nakashima, 2002). Three of these species, F. takahashii (Yokoyama, 1930), F. kenyoshiensis Chinzei, 1960, and F. hallae Dall, 1921, have the widest biogeographic distribution in circum-North Pacific Neogene faunas. Of these three, F. takahashii and F. kenyoshiensis have been found in Honshu, Hokkaido, Sakhalin, and Kamchatka (northwestern Pacific). The third species, F. hallae, is the one species that occurs in both Kamchatka and Alaska (Fig. 1). Fortipecten hallae has been found in Pliocene deposits of Karaginskiy Island (northeastern Kam-

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Table 1 Presently known valid species of Fortipecten, their type localities, and distribution in the North Pacific Species of the genus Fortipecten (Yabe and Hatai, 1940)

Type locality and age

Distribution in the North Pacific

F. Hallae (Dall, 1921)

One mile from the Delta of Solomon River, Nome Region, Seward Peninsula, Alaska, bSubmarine BeachQ, Beringian beds, upper Pliocene Southeastern Sakhalin, Makarov district, vicinity of Tumanovo, Maruyama formation, lower Pliocene To the North of the mouth of Vengeri River, Schmidt Peninsula, northern Sakhalin, Pomyrskaya Formation, lower Pliocene Pobedinka (Koton) River, Poronaisk Region, southern Sakhalin, Maruyama Formation, lower Pliocene 0.5 km to the West of Kenyoshi, Nagawa, Sannohe distict, Aomori Prefecture, northern Honshu, Togawa Formation, lower Pliocene Gornaya river, Makarov Region, southeastern Sakhalin, Maruyama Formation, lower Pliocene Vicinity of the Karasuzawa dam on the Nakano River, Kuroishi, Aomori Prefecture, northern Honshu, Ogawara Formation, middle Miocene Southeastern Sakhalin, Makarov district, Kormovaya River, lower member of the Maruyama Formation, upper Miocene

Alaska and northeastern Kamchatka Honshu, Hokkaido, Sakhalin, and Kamchatka Northern Sakhalin

F. takahashii (Yokoyama, 1930) F. mironovi (Khomenko, 1934) F. sachalinensis (Ilyina, 1954) F. kenyoshiensis Chinzei, 1960 F. makarovi L. Krishtofovich, 1964 F. kuroishienesis Kotaka and Noda, 1967 F. maruyamensis Barinov, 2001

chatka) (Gladenkov, 1972; Sinelnikova, 1975; Basilyan et al., 1991; Gladenkov et al., 1992), western Alaska (the Solomon and Kivalina areas) (Hopkins and MacNeil, 1960; MacNeil et al., 1943; MacNeil, 1967), and northern Alaska (lower Colville River) (Marincovich and Powell, 1991) (Fig. 1). Until recently, only the northeastern Kamchatka occurrence of F. hallae (in the lower part of the Limimtevayamskaya Formation on the Karaginskiy Island) had been dated from independent evidence (diatoms and paleomagnetic data), as early Pliocene (Basilyan et al., 1991; Gladenkov et al., 1991, 1992). There was

Fig. 1. Fortipecten hallae localities in the North Pacific mentioned in the text.

Southern Sakhalin, western Kamchatka(?) Honshu, western Kamchatka, Sakhalin(?) Southeastern Sakhalin Honshu Southeastern Sakhalin

disagreement about the exact age of F. hallae occurrences (MacNeil, 1967) in Alaska. Hopkins (1967) conditionally assigned F. hallae to faunal assemblages of the bBeringian transgression.Q The stratotype of these deposits was cited by MacNeil et al. (1943) as a submarine (i.e., buried) beach deposit on the Seward Peninsula near Nome, northwestern Alaska but they did report occurrence of F. hallae there as buncertainQ. The occurrence of F. hallae has been confirmed for two localities in northwestern Alaska: (1) near Solomon village, and (2) along the coast of Kotzebue Sound near Kivalina village (Hopkins and MacNeil, 1960; MacNeil, 1967) (Fig. 1). We refer to these two localities as Solomon and Kivalina, respectively. Hopkins (1967) assigned deposits at Kivalina and Solomon (Fig. 1) to the late Pliocene Beringian transgression, based on their molluscan faunal composition and stratigraphic relationships. Deposits at the Nome (stratotype) and Solomon localities are subsurface beach deposits and overlie Mesozoic basement rocks hypsometrically below present-day sea level. F. hallae is abundant at Solomon, but the molluscan assemblage there (Fig. 1) has no other species in common with Nome (MacNeil, 1967). At Kivalina, in contrast, F. hallae co-occurs with several mollusk species that also are found at Nome (Hopkins and MacNeil, 1960). MacNeil (1967) observed that thick-shelled fragments of F. hallae at Kivalina were more worn than co-occurring thin-

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shelled bivalves, and inferred that F. hallae could have been reworked from deposits of greater age. The exact geographic and stratigraphic placement of F. hallae localities have not always been accurately known. For example, MacNeil et al. (1943) cited one locality as: bBuried Pliocene beach, 20 feet below surface, near Solomon River, Nome District, Alaska, Collector, Otto HallaQ. According to Dr. P.S. Smith, Chief Alaskan Geologist, bOtto Halla was a miner who mainly worked near Nome in deposits of submarine (i.e., buried) beaches and not on Solomon RiverQ (MacNeil et al., 1943). This information suggests that evidence for bin situQ occurrences of the F. hallae in Beringian transgression deposits is ambiguous at best. However, several specimens of F. hallae that we collected from the Milky River Formation, on the distal part of the Alaska Peninsula, southwestern Alaska, at 56870V N 159892V W (Fig. 1), shed new light on the geographic occurrences and age of F. hallae.

2. Geologic setting The specimens of F. hallae that are the focus of this study come from the Sandy Ridge stratigraphic section of the Milky River Formation (Figs. 1-3: 2–4; Fig. 4: 2–3). The geological setting, a general stratigraphic description of this section, and a geological map of the Sandy Ridge area are given in Marincovich et al. (2002) and Gladenkov et al. (2002). The Sandy Ridge section consists entirely of shallowmarine sediments with abundant fossils, which make it the only known Milky River Formation section that is not largely of non-marine aspect. Our measured stratigraphic section of the Milky River Formation at Sandy Ridge consists of 276 m of shallow-marine sediments. These marine beds are inferred to be overlain by approximately 200 m of non-marine volcaniclastic sediments and basalt flows that crop out to the west along Sandy Ridge and are identical to nonmarine lithologies elsewhere in the Milky River

Fig. 2. Measured stratigraphic section of the Milky River Formation at Sandy Ridge, with plotted occurrences of F. hallae, A. (T.) borealis and available numeric ages.

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Fig. 3. Fortipecten hallae (Dall, 1921): 1,5—Specimen GIN 8719/2, NE Kamchatka, Karaginskiy Island, lower part of the Limimtevayamskaya Formation. 1—right valve 0.7; 5—side view 0.7; 2–4—right valves: 2—Specimen CAS LM16/1, latex cast, Alaska Peninsula, Sandy Ridge, 0.9; 3—Specimen CAS LM16/2, latex cast, Alaska Peninsula, Sandy Ridge 0.8; 4—Specimen CAS LM46/1, latex cast, Alaska Peninsula, Sandy Ridge 0.8.

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Fig. 4. Fortipecten hallae (Dall, 1921) left valves: 1— Specimen GIN 8731/83, NE Kamchatka, Karaginskiy Island, base of the upper part of the Limimtevayamskaya Formation 0.9; 2—Specimen CAS LM46/2, latex cast, Alaska Peninsula, Sandy Ridge0.9; 3—Specimen CAS LM16/3, Alaska Peninsula, Sandy Ridge 0.8; 4—Specimen GIN 8719/2, NE Kamchatka, Karaginskiy Island, lower part of Limimtevayamskaya Formation 0.6. Abbreviations: GIN—Geological Institute of the Russian Academy of Sciences, Moscow, Russia; CAS—California Academy of Sciences, San Francisco, CA.

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Formation (Lyle et al., 1979; Detterman et al., 1996). The Sandy Ridge marine beds lie with profound angular unconformity upon a folded terrestrial sequence of inferred middle Miocene age (Marincovich et al., 2002; Gladenkov et al., 2002). The marine portion of the Sandy Ridge beds consists of two lithologically distinct members (Fig. 2). The lower member, with the exception of a 3.5-mthick basal conglomerate, is represented by 112 m of fine-grained grey sandstone interbedded with thinner (0.7–1 m) layers of coarser-grained pebbly sandstone. Strata also contain several thin (up to 0.1 m thick) ash and gravel beds and elongate concretions up to 0.5 m long. Smaller concretions often merge into concretionary horizons up to 0.4 m thick. Floating pebbles are scattered throughout these marine strata. The molluscan assemblage of the lower member include the bivalves Acila (Truncacila) empirensis Howe, 1922, Astarte (Tridonta) borealis (Schumacher, 1817), Ciliatocardium ex gr. ciliatum (Fabricius, 1780), Clinocardium pristinum Keen, 1954, Macoma calcarea (Gmelin, 1791), Musculus niger (Gray, 1824), Mya truncata Linnaeus, 1758, Pandora (Pandorella) wardiana A. Adams, 1860, Panomya norvegica Spengler, 1793, Serripes (Serripes) groenlandicus (Mohr, 1786), Spisula voyi (Gabb, 1866) and Yoldia (Cnesterium) seminuda Dall, 1871, plus the gastropods Beringius hertleini MacNeil, 1970, Boreotrophon beringi Dall, 1902, Buccinum glaciale (Linne, 1761), B. polium polium (Dall, 1907), Colus (Latisipho) aurantius (Dall, 1925), Clinopegma unicum(Pilsbry, 1905), Cryptonatica clausa (Broderip and Sowerby, 1829), Neptunea lyrata altispira (Gabb, 1869), Obesotoma solida (Dall, 1886) and Volutopsius middendorffi (Dall, 1891). The upper member of the Sandy Ridge section consists of 161 m of massive, mostly tuffaceous sandstones, gravels, and conglomerates (Fig. 3). The lower 50 m of this upper member consists of interbedded medium-grained dark-gray to yellowishgray tuffaceous sandstone (layers 1.2–15 m thick) and massive, dark-gray to greenish-gray, occasionally cross-bedded sandstone (layers 1–10 m thick) with pebble, gravel, and conglomerate horizons. These massive sandstones form distinctive vertical cliffs in the slope. The tuffaceous sandstone contains abundant mollusks, including Acila (Truncacila) empirensis, Astarte (Tridonta) borealis, Ciliatocardium ex gr.

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ciliatum, Clinocardium pristinum, Cyclocardia kamtschatica (Slodkevitsch, 1938), Diplodonta aleutica Dall, 1901, Macoma calcarea, Macoma obliqua (Sowerby, 1812), Musculus niger, Mya truncata, Pandora (Pandorella) wardiana, Panomya norvegica, Serripes groenlandicus, Siliqua alta (Broderip and Sowerby, 1829) and Yoldia (Cnesterium) seminuda, plus the gastropod Neptunea lyrata altispira. Mollusk specimens are usually localized within thin horizons and lenses. Massive sandstone and conglomerate beds contain abundant molds and casts of Mya truncata. The upper 111 m of the upper member of the marine facies at Sandy Ridge consists of mediumto coarse-grained, poorly lithified, dark gray, tuffaceous sandstones with a 0.3-m basal conglomerate separated from underlying beds by an erosional contact. Portions of the sandstone beds are bioturbated. The sandstone includes layers of darker-gray, poorly sorted gravel and conglomerate (from 0.1 to 15 m thick), and the degree of lithification decreases, and grain size increases, up-section. These strata contain the following molluscan assemblage: the bivalves Ciliatocardium ciliatum, Clinocardium nuttallii (Conrad, 1837), Fortipecten hallae (Figs. 3 —2–4 and 4 — 2–3), Macoma calcarea, Mizuhopecten sp., Mya truncata, Peronidia lutea (Wood, 1828), Pododesmus macroshisma (Deshayes, 1839) and Protothaca staminea (Conrad, 1837), plus the gastropod Neptunea lyrata altispira. The lower member and lower 50 m of the upper member, of the studied stratigraphic section, are characterized by the same boreal molluscan assemblage. All genera and some of the extant species in this assemblage inhabit the upper-subtidal zone in the Bering Sea and the Sea of Okhotsk today, being most abundant at depths from 5 to 75 m (Scarlato, 1981; Kuznetsov, 1963; Coan et al., 2000). Mollusks in the lower part of the section are preserved with shell mostly intact and in living position. Disarticulated valves and shell fragments dominate preservation in the basal 50 m of the upper member. A change in the preservation and orientation of mollusk shells implies a change in depositional environment from relatively quiet in the lower member, to more hydrodynamically active at the beginning of the upper member part (Fig. 2). The geology, localities and age of Kamchatka localities were described in detail by Gladenkov et al. (1992). Specimens of F. hallae from the Limimte-

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vayamskaya Formation of the Karaginskiy Island, northeastern Kamchatka, are figured for comparative purpose (Fig. 3 —1, 5 and Fig. 4 —1, 4).

3. Discussion Fossil large pectinids from the North Pacific margin have long been considered as biogeographic and paleoclimatic indicators. Two species of large pectinids are now known from the vicinity of the Sandy Ridge locality—F. hallae and Mizuhopecten mollerensis (MacNeil, 1967). Specimens from Sandy Ridge are identified as F. hallae using the features of surface sculpture described in detail by MacNeil (1967) and Masuda (1978). We have found a shell fragment of Mizuhopecten sp. co-occurring with F. hallae in the Sandy Ridge section. However poor preservation of the fragment precludes species identification. It should also be noted that the age of occurrence for M. mollerensis is not known. We made a dedicated attempt during field work on the Alaska Peninsula in 1999 to find its type locality, but we were unsuccessful. This locality may have been eroded away, or may have been covered by the very dense vegetation there. The lower member of the marine facies of the Milky River Formation at Sandy Ridge contains the oldest Cenozoic occurrences in the North Pacific of the bivalve Astarte (Marincovich and Gladenkov, 1999; Marincovich et al., 2002). This occurrence correlates with subzone b of the Neodenticula kamchatica diatom zone of Barron and Gladenkov (1995), which has an age range of 5.5–4.8 Ma (Marincovich and Gladenkov, 1999, 2001). This occurrence of Astarte was later refined to 5.5–5.4 Ma, based on a diatom assemblage from the lowermost occurrence of Astarte in the section (28 m above the base of the section) (Fig. 2) (Gladenkov et al., 2002; Gladenkov, 2003), which implies that the accumulation of the lower part of the marine member of the Milky River Formation took place at the very end of the Late Miocene—beginning of the Early Pliocene. The upper part of the Milky River Formation at Sandy Ridge, containing remains of F. hallae, based on the first appearance and disappearance of the indicative North Pacific diatom species, is assigned to the interval of 5.1–4.8 Ma (Gladenkov et

al., 2002; Gladenkov, 2003). The potassium–argon age of a basalt flow in the uppermost part of the Milky River Formation at its nearby type locality is 3.87 F 0.06–3.53 F 0.27 Ma (Fig. 2) (Detterman et al., 1996; Wilson et al., 1981). This age assignment supports the suggestion of MacNeil (1967) that beds with F. hallae at the Solomon locality could have been older than the submarine beach deposits at Nome. The age of F. hallae in the Milky River Formation is similar to its age in the lower part of the Limimtevayamskaya Formation on Karaginskiy Island (northeastern Kamchatka) (Fig. 1), based on paleomagnetic and diatom data that imply an age range of 4.5–4.1 Ma (Basilyan et al., 1991; Gladenkov et al., 1991, 1992). Using latest data and scale of Berggren et al. (1995), shifts this interval to 5.0–4.3 Ma. These age data suggest that F. hallae first appeared in the Bering Sea region in the early Pliocene. The appearance of F. hallae in Alaska, together with two other species—F. takahashii, and F. kenyoshiensis in western Kamchatka (Sinelnikova, 1975), suggest that the genus Fortipecten had originated in the northern Japan and Sakhalin Island and then migrated to the high-latitude North Pacific in the early Pliocene. The spread of F. hallae in the highlatitude North Pacific coincided with the onset of a relatively warm marine climate in the Bering, Beaufort, and Chukchi seas during the early Pliocene. Oxygen isotope values from Cyclocardia and Macoma co-occurring with F. hallae in the Limimtevayamaskaya Formation of Karaginskiy Island suggest a rise in the water temperature of approximately 3.2–4.5 8C in comparison with older deposits immediately below (Barinov and Kiyashko, 1997). The methodology and discussion of the y18O values for the early Pliocene mollusks of Karaginskiy Island are given in Gladenkov et al. (1992). Comparable isotopic data from the Milky River Formation do not exist, due to shell recrystallization. The appearance of F. hallae in both Kamchatka and Alaska was accompanied by a conspicuous change in the molluscan assemblage. In both regions, this biostratigraphic interval is marked by the appearance of mollusks indicative of warmer water conditions than those usually encountered at these latitudes today. This change in the molluscan assemblage in the Milky River Formation was observed between the lower 50 m and upper 111 m of the upper part of the marine unit. This stratigraphic

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interval of the Milky River Formation is marked by the first appearance of Fortipecten, Prothothaca Dall, 1902, and Mizuhopecten Masuda, 1963; none of these mollusks are found in the lower part of the section. These occurrences imply a shallow, inner-subtidal deposition and a mild marine climate. Synchronous changes in molluscan assemblages in Kamchatka and Alaska suggest that the early Pliocene marine climate was probably comparable with the present-day climate of southern Sakhalin (Gulf of Aniva) (Scarlato, 1981).

4. Taxonomic note According to Article 11g, Recommendation 31A, and Appendix D III of the International Code of Zoological Nomenclature (1985), species-group names formed from modern personal names, should usually end in -i or -orum, if the personal name is that of a man. Because Fortipecten hallae was named after a man, Otto Halla, the correct spelling of the species name should have been, F. hallai (not F. hallae).

Acknowledgements This research was funded by National Science Foundation, Arctic Natural Sciences Program grant OPP 9806461 to L. Marincovich. We thank Rei Nakashima of the Geological Survey of Japan for the opportunity to examine fortipectens from northern Japan, and for useful discussions in the course of this study. We are grateful to Julie Brigham-Grette of the University of Massachusetts for a helpful and stimulating review of the manuscript.

References Adams, A., 1860. Description of new conchiferous mollusk of the genus Pandora. Proceedings for 1859, vol. 27(3). Zoological Society of London. 487 pp. Barinov, K.B., 2001. New data on the distribution of the bivalve genus Fortipecten in the Maruyama Formation of southeastern Sakhalin. Paleontological Journal 35 (3), 249 – 253. Barinov, K.B., Kiyashko, S.I., 1997. Climatic implications of the bivalve Fortipecten hallae (Dall) in the Alaskan Pliocene.

169

Beringia Paleoenvironments Workshop, Abstracts with Programs, p. 11. Barron, J.A., Gladenkov, A.Yu., 1995. Early Miocene to Pleistocene diatom stratigraphy of Leg 145. In: Rea, D.K., Basov, I.A., Scholl, D.W., Allan, J.F. (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, vol. 145. Ocean Drilling Program, College Station, TX, pp. 3 – 19. Broderip, W.J., Sowerby, G.B., 1829. Observations on new and interesting mollusca contained, for the most part, in the museum of the Zoological Society. Journal of Zoology 4, 359 – 375. Basilyan, A.E., Barinov, K.B., Oreshkina, T.V., Trubikhin, V.M., 1991. Pliocene transgressions of the Bering Sea. In: Vangengeim, E.A. (Ed.), Biostratigraphy of Pliocene and Antropogene. U.S.S.R. Academy of Sciences Geological Institute, Moscow, pp. 5 – 24. Berggren, W.A., Kent, D.V., Swisher, C.C., Aubry, M.-P., 1995. A revised Cenozoic geochronology and chronostratigraphy. In: Berggren, W.A., Kent, D.V., Aubry, M.-P., Hardebol, J. (Eds.), Geochronology, Time Scales, and Global Stratigraphic Correlations: Unified Temporal Framework for Historical Geology, SEPM Special Publication, vol. 54, pp. 129 – 212. Chinzei, K., 1960. A new Fortipecten from the Pliocene Sannohe Group in Aomori Prefecture, Northeast Japan. Japanese Journal of Geology and Geography 31 (1), 63 – 70. Coan, E.V., Scott, P.V., Bernard, F.R., 2000. Bivalve seashells of Western North America, Marine Bivalve Mollusks from Arctic Alaska to Baja California. Santa Barbara Museum of Natural History, Monographs 2, Studies in Biodiversity 2, 764 pp. Conrad, T.A., 1837. Descriptions of new marine shells from Upper California, collected by Thomas Nuttall, Esq, Journal, vol. 7(2). Academy of Natural Sciences of Philadelphia, pp. 227 – 268. Dall, W.H., 1871–1872. Descriptions of sixty new forms of mollusks from the west coast of North America and the North Pacific Ocean, with notes on others, already described. American Journal of Conchology, 7(2), 93–160. Dall, W.H., 1886. Contributions to the natural history of the Commander Islands, No. 6. Report on the Bering Island Mollusca collected by Mr. Nikolas Grebnitzki: United States National Museum. Proceedings 9 (562), 209 – 219. Dall, W.H., 1891. Scientific results of explorations by the U.S. Fish Commission steamer Albatross: XX. On some new or interesting west American shells obtained from the dredgings of the U.S. Fish Commission steamer Albatross in 1888, and from other sources, United States National Museum. Proceedings 14 (849), 174 – 191. Dall, W.H., 1901. Synopsis of the Lucinacea and of the American species, United States National Museum. Proceedings 23 (1237), 779 – 833. Dall, W.H., 1902. Synopsis of the family Veneridae and of the North American recent species, United States National Museum. Proceedings 26 (1312), 335 – 412. Dall, W.H., 1907. Descriptions of new species of shells, chiefly Buccinidae, from the dredging of the U.S.S. bAlbatrossQ during 1906, in the north-western Pacific, Bering, Okhotsk, and Japanese seas. Smithsonian Miscellaneous Collections 50 (2), 139 – 173 (N1727).

170

K.B. Barinov et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 223 (2005) 162–171

Dall, W.H., 1921. Two new Pliocene pectens from Nome Alaska. The Nautilus 34 (3), 76 – 77. Dall, W.H., 1925. Illustrations of unfigured types of shells in the collection of the United States National Museum, United States National Museum. Proceedings 66 (17), 1 – 41. Deshayes, G.P., 1839. Nouvelles especes de mollusques, provenant des cetes de Californie, du Mexique, de Kamtschatka et de Nouvelle-Zeelande,. . .: Societe Cuvierienne. Revue Zoologique 2 (12), 356 – 361. Detterman, R.L., Case, J.E., Miller, J.W., Wilson, F.H., Yount, M.E., 1996. Stratigraphic framework of the Alaska Peninsula. U.S. Geological Survey Professional Paper, vol. 1969-A. 74 pp. Fabricius, O., 1780. Fauna Groenlandica, systematice sistens Animalia Groenlandiae occidentalis hactenus indagata, . . . Hafniae and Lipsiae (Rothe). 452 pp. Gabb, W.M., 1866–1869. Palaeontology of California: Volume 2. Cretaceous and Tertiary fossils. Section 1, Tertiary invertebrate fossils. Geological Survey of California. 124 p. Gladenkov, Yu. B., 1972. The Neogene of Kamchatka: Problems of biostratigraphy and paleoecology. U.S.S.R. Academy of Sciences, Geological Institute. Transactions, vol. 214. Nauka Publisher, Moscow. (252 pp. [in Russian]). Gladenkov, A.Yu., 2003. Diatom biostratigraphy of the Neogene Milky River Formation, Alaska Peninsula, southwestern Alaska. Proceedings of the California Academy of Sciences 54 (3), 27 – 64. Gladenkov, Yu. B., Barinov, K.B., Basilyan, A.E., Cronin, T.M., 1991. Stratigraphy and paleoceanography of Miocene deposits of Karaginsky Island, eastern Kamchatka, U.S.S.R. Quaternary Science Reviews 10, 239 – 245. Gladenkov, Yu. B., Barinov, K.B., Basilian, A.E., Bordunov, S.I., Bratseva, G.M., Zyrianov, E.P., Kuralenko, N.P., Vitukhin, D.I., Oreshkina, T.V., Ganzei, S.S., Kiyashko, S.I., Trubikhin, V.M., 1992. Detailed division of the Neogene of Kamchatka. Nauka Publishers, Moscow. (208 pp. [in Russian]). Gladenkov, A.Yu., Oleinik, A.E., Marincovich Jr., L., Barinov, K.B., 2002. A refined age for the earliest opening of Bering Strait. Palaeogeography, Palaeoclimatology, Palaeoecology 183, 321 – 328. Gmelin, J.F., 1791. Caroli a Linne` . . . Systema naturae per regna tria naturae . . . edito decimal tertia, acuta, reformata. Leipzig (Beer) 1 (6), 3021 – 3910. Gray, J.E., 1824. Shells. Pp. ccxl–ccxlvi. A supplement to the Appendix of Captain Parry’s voyage for the discovery of a north-west passage, in the years 1819–20 containing an account of the subjects of natural history. London (Murray): clxxxiii–cccx. Hopkins, D.M., 1967. Quaternary marine transgressions in Alaska. In: Hopkins, D.M. (Ed.), The Bering Land Bridge. Stanford University Press, Stanford, California, pp. 47 – 90. Hopkins, D.M., MacNeil, F.S., 1960. A Marine Fauna Probably of Late Pliocene Age Near Kivalina, Alaska, U. S. Geological Survey Professional Paper, vol. 400-B, pp. 339 – 342. Howe, H.V., 1922. Faunal and Stratigraphic Relationships of the Empire Formation, Coos Bay, Oregon, Department of Geological Sciences Bulletin, vol. 14(3). University of California Publications, pp. 85 – 114.

Ilyina, A.P., 1954. Mollusks of the Neogene deposits of the southern Sakhalin. In: Krishtofovich, L.V., Ilyina, A.P. (Eds.), Mollusks of Tertiary deposits of the southern Sakhalin, Transactions of the All-Union Petroleum Research Institute (VNIGRI), vol. 10. Leningrad, Gostoptechizdat, pp. 188 – 252 (in Russian). International Code of Zoological Nomenclature, 1985. In: Ride, W.D., Sabrosky, G.W., Bernardi, G., Melville, R.V. (Eds.), Third Edition Adopted by the XX General Assembly of the International Union of Biological Sciences. University of California Press. 202 pp. Kafanov, A.I., 1986. Systematics and geological history of the subfamily Fortipecteninae Masuda 1963 (Bivalvia, Pectinidae). In: Kafanov, A.I., Levin, V.S., Beniaminson, T.S. (Eds.), Paleogene–Neogene Bivalve Mollusks of the Far East and Eastern Paratethys, Far Eastern Branch of the U. S. S. R. Academy of Sciences. Institute of Marine Biology, Vladivostok, pp. 18 – 46. Keen, A.M., 1954. Five new species and a new subgenus in the pelecypod family Cardiidae. Bulletins of American Paleontology 35 (153), 307 – 330. Khomenko, I.P., 1934. Stratigraphy of tertiary beds of the Schmidt Peninsula (northern Sakhalin). Transactions of the All-Union Petroleum Research Institute (VNIGRI), Series A, vol. 79. Leningrad, Nedra (86 pp. [in Russian]). Kotaka, T., Noda, H., 1967. Miocene mollusca from the MinamiTsugaru district, Amori Prefecture, Northeast Japan. Research Bulletin of the Saito Ho-on Kai Museum 36, 33 – 47. Krishtofovich, L.V., 1964. Mollusks from the Tertiary deposits of Sakhalin. Transactions of the All-Union Petroleum Research Institute (VNIGRI), vol. 232. Leningrad, Nedra (343 pp. [in Russian]). Kuznetsov, A.P., 1963. Fauna of bottom invertebrates of Kamchatka waters of the Pacific Ocean and northern Kurile Islands. Nauka Publishers, Moscow. 271 pp. Linnaeus, C., 1758. Systema naturae per regna tria naturae . . .edito decimal reformata, vol. 1 (Regnum animale). Stockholm (Salvii), 824 + iii pp. Linne, C., 1761. In: Holmia (Ed.), Systema Naturae, vol. 11. 578 pp. Lyle, W.M., Morehouse, J.A., Palmer Jr., I.F., Bolm, J.G., 1979. Tertiary formations and associated Mesozoic rocks in the Alaska Peninsula area, Alaska, and their petroleum—reservoir and source-rock potential. Alaska Division of Geological and Geophysical Surveys Geologic Report. 62. 65 pp. MacNeil, F.S., 1967. Cenozoic Pectinids of Alaska, Iceland and other Northern Regions. U. S. Geological Survey Professional Paper 533. 57 pp. MacNeil, F.S., 1970. New Pliocene Chlamys (Swiftopecten) and Beringius from the Alaska Peninsula. The Nautilus 84 (2), 69 – 74. MacNeil, F.S., Martie, J.B., Pilsbry, H.A., 1943. Marine invertebrate faunas of the buried beaches near Nome, Alaska. Journal of Paleontology 17 (1), 69 – 96. Marincovich Jr., L., Powell II, C.L., 1991. Pliocene and Pleistocene mollusks in marine transgressions of western and northern Alaska: The Western Society of Malacologists. Annual Report 23, 10 – 14.

K.B. Barinov et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 223 (2005) 162–171 Marincovich Jr., L., Gladenkov, A.Yu., 1999. Evidence for an early opening of the Bering Strait. Nature 397, 149 – 151. Marincovich Jr., L., Gladenkov, A.Yu., 2001. New evidence for the age of Bering Strait. Quaternary Science Reviews 20, 329 – 335. Marincovich Jr., L., Barinov, K.B., Oleinik, A.E., 2002. The Astarte (Bivalvia, Astartidae) that document the earliest opening of Bering Strait. Journal of Paleontology 76 (2), 239 – 245. Masuda, K., 1963. The so-called Patinopecten of Japan. Palaeontological Society of Japan, Transactions and Proceedings 52, 145 – 153. Masuda, K., 1978. Neogene Pectinidae of the Northern Pacific. The Veliger 21 (2), 197 – 202. Mohr, N., 1786. Forsug til en Islandsk Naturhistorie, Med Adskilligeoekonomiske Samt Andre Anmaerkninger. Holm, Copenhagen, p. 129. Nakashima, R., 2002. Geographic distribution of the late Cenozoic bivalve Fortipecten in the northwestern Pacific. Palaeogeography, Palaeoclimatology, Palaeoecology 186, 261 – 274. Pilsbry, H.A., 1905. Naw Japanese Marine Mollusca, Proceedings, vol. 57. Academy of Natural Sciences of Philadelphia, pp. 101 – 122 (for 1905). Scarlato, O.A., 1981. Bivalve mollusks of temperate latitudes of the western part of the Pacific Ocean. Survey of the Fauna of the U.S.S.R., Transactions of the U.S.S.R. Academy of Sciences Zoological Institute, 126. Nauka Publishers, Leningrad, 479 pp. (in Russian). Schumacher, C.F., 1817. Essai D’un Nouveau Syste` me des Habitations des vers Testaceos. Copenhagen, 287 pp., 22 pls. Sinelnikova, V.N., 1975. Mio–Pliocene Pectinidae of Kamchatka. U. S. S. R. Academy of Sciences Geological Institute. Transactions 229. 144 pp.

171

Slodkevitsch, V.S., 1938. Tertiary pelecypods of the Far East. In: Paleontology of the U.S.S.R., Moscow–Leningrad, Academy of Sciences Publisher, Part I 10(3) (18), 508 pp. (in Russian). Sowerby, J. de C., 1812–1846. The mineral conchology of Great Britain: or coloured figures and descriptions of those remains of testaceous animals or shells, which have been preserved at various times and depths in the earth. Benjamin Meredith, London, 7 volumes. Spengler, L., 1793. Beskrivelse over et nyt slaegt af de toskallede konkylier, forhen af mig kaldet Chaena, saa og over det Linne`iste slaegt Mya, hvilket nbire bestemmes og inddeles I tvende slaegter. Kobenhavn, Naturhistorie-Selskabet, Skrivter 3(1), 16–59. Wilson, F.H., Gaum, W.C., Herzon, P.L., 1981. Maps and tables showing geochronology and whole-rock geochemistry, Chignik and Sutwik Island quadrangles, Alaska: U.S. Geological Survey Miscellaneous Filed Studies, Map MF-1053-M, scale 1:250,000. Wood, W., 1828. Supplement to the Index Testaceologicus; or a Catalogue of Shells British and Foreign. Wood, London. 59 pp. Yabe, H., Hatai, K., 1940. A note on Pecten (Fortipecten, subgen. nov.) takahashiiYokoyama and its bearing on the Neogene deposits of Japan: Science Reports of the Tohoku Imperial University, Series 2, 21(2), 147–160. Yokoyama, M., 1930. Tertiary Mollusca from South Karafto, Journal of Faculty of Science, vol. 2(10). Imperial University, Tokyo, pp. 407 – 418 (Section 2).