Paleobiogeographical implications of inner bay Ostracoda during the Late Pleistocene Shimosueyoshi transgression,central Japan,with significance of its migration and disappearance in eastern Asia |
| |
| Authors: | Toshiaki Irizuki Hajime Taru Kiminori Taguchi Yoshiaki Matsushima |
| |
| Institution: | 1. School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China;2. Swire Institute of Marine Science, The University of Hong Kong, Cape d''Aguilar Road, Shek O, Hong Kong SAR, China;3. Research Center for Coastal Lagoon Environment, Shimane University, Matsue 690-8504, Japan;4. Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan;5. Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;1. School of Biological Sciences, Department of Earth Sciences, Swire Institute of Marine Science, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong, China;2. Nagasaki Prefectural Government, 2-13 Edo, Nagasaki City, Nagasaki 850-8570, Japan;3. Department of Geoscience, Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue City, Shimane 690-8504, Japan;1. Department of Geoscience, Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu-cho, Matsue 690-8504, Japan;2. Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-ku, Kobe 657-8501, Japan;3. Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan;4. Japan Agency for Marine-earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan |
| |
| Abstract: | A total of 79 ostracode species were recognized from the embayment sediments deposited during the Late Pleistocene Shimosueyoshi transgression in central Japan. The most dominant species was Neomonoceratina delicata, now abundant in tropical inner bays of the Ryukyu Islands, the South China Sea and southeastern Asia. Bicornucythere bisanensis, widely dominant species in enclosed middle muddy bays of temperate climatic zones in Japan and northern China, was also abundant in the middle and upper sequences. Most of the other main species were assigned to the “Japonic elements” and are presently common in tropical or subtropical and temperate shallow seas near the Japanese Islands. Four ostracode biofacies were identified using the Q-mode cluster analysis. A change in water depth was clearly revealed in the study sequence, based on the vertical changes in the biofacies and the relative abundances of fossil ostracode species. The single most dominant species, N. delicata, does not currently exist in the Japanese Islands north of the Tokara Strait (Watase's line: one of zoological lines of demarcation), in southern Japan. Based on a compilation of fossil and recent distribution records, it is believed that N. delicata migrated from the south of the Tokara Strait by the marine oxygen isotope stage (MIS) 11 (～ 430 ka), dominated other species in enclosed muddy bays and then spread to the northernmost areas during the MIS 5. However, almost all populations of this species probably disappeared north of the Tokara Strait during the Last Glacial Maximum due to a decrease in water temperature. This species could not survive colder water temperature and could not migrate north through the Tokara Strait during the postglacial transgression because the strait has been deep and wide since the Early Pleistocene. We conclude that this species lived commonly during the glacial stages of MIS 10, 8 and 6 north of the Tokara Strait because of the favorable water temperature for reproduction. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
