Summary of the fossil record of pinnipeds of Japan, and comparisons with that from the eastern North Pacific |
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| Authors: | Shigeo Miyazah Hideo Horkawa Naoki Kohno Kiyoharu Hirota Masaichi Kimura Yoshkazu Hasegawa Yukimitsu Tomida Lawrence G Barnes Clayton E Ray |
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| Institution: | Oomama High School, 3-64-2-35, Aioi-cho, Kiryu-shi, Gunma 376, Japan;Ojiyanishi High School, Ojiya, Niigata 947, Japan;Department of Geology, National Science Museum (Natural History Institute), 3-23-1 Hyakunin-cho, Shinjuku-ku, Tokyo 169, Japan;Japan Foundation Engineering Company, 6-22, Matsugae-cho, Kita-ku, Osaka 530, Japan;Hokkaido University of Education, Sapporo 002, Japan;Geological Institute, Faculty of Education, Yokohama National University, Yokohama, Japan;Department of Geology, National Science Museum, Tokyo 169, Japan;Section of Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, CA 90007, USA;Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA |
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| Abstract: | Abstract The fossil pinniped record of the North Pacific Ocean includes both Phocidae and Otariidae ( sensu lato ), extends from the Late Oligocene to the Late Pleistocene, is taxonomically diverse, and is constantly becoming more complete owing to additional important discoveries. The earliest and most diverse fossil pinnipeds in the North Pacific are otariids, the phocids not appearing until the latest Pliocene. The theoretical center of otariid pinniped evolutionary history has been considered by some to be in the eastern North Pacific. New materials from the western North Pacific, however, including representatives of the subfamilies Enaliarctinae, Imagotariinae, Odobeninae and Otariinae, indicate that pinniped evolutionary patterns were basin-wide phenomena, and that a more complete record undoubtedly would reveal numerous trans-Pacific distributions. This would be expected considering the distributions of living species. The paucity of fossil Phocidae and their absence from pre-Pliocene deposits are consistent with theories that the family primarily evolved outside the North Pacific. |
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| Keywords: | classification fossil pinnipeds North Pacific Otariidae paleobiogeography Phocidae |
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