Literaturdatenbank
Literaturdatenbank |
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Yasukawa, Y., & Ota, H. , Geographic variation and biogeography of the geoemydine turtles (testudines: bataguridae) of the ryukyu archipelago, japan. Unpublished paper presented at Proceedings of the International Symposium, "Diversity of Reptiles, Amphibians, and Other Terrestrial Animals on Tropical Islands: Origin, Current Status, and Conservation", held at the University of the Ryukyus, Okinawa, Japan, from 6 to 7 June 1998.
Added by: Sarina Wunderlich (27 Mar 2011 16:16:50 UTC) |
| Resource type: Conference Paper BibTeX citation key: Yasukawa1999 View all bibliographic details  |
Categories: General Keywords: Geoemyda, Geoemyda japonica, Geoemyda spengleri, Geoemydidae, Habitat = habitat, Mauremys, Mauremys japonica, Mauremys mutica, Ostasien = East Asia, Schildkröten = turtles + tortoises Creators: Ota, Yasukawa Collection: Proceedings of the International Symposium, "Diversity of Reptiles, Amphibians, and Other Terrestrial Animals on Tropical Islands: Origin, Current Status, and Conservation", held at the University of the Ryukyus, Okinawa, Japan, from 6 to 7 June 1998 |
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| Abstract |
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Three geoemydine species, Geoemyda japonica, Mauremys mutica and Cistocemmys flavomarginata, occur in the Ryukyu Archipelago, Japan. Of these, G. japanica is restricted to the central Ryukyus, with its dosest relative, G. spengleri, being distantly distributed in southeastem continental China and northern Indochina. A recent comparative study demonstrated remarkable differences between these species in a number of qualitative characters. The other two species, while confined within the archipelago to its southem part, also occur in Taiwan and southem continental China. In both species, the Ryukyu populations are most divergent among conspecific populations. Nevertheless, there were only quantitative (Ie., statisticaI) differences in most single characters between the southem Ryukyu and other populations, and the degrees of.their differences are thus substantially lower than that between G. japonica and G. spengleri. Such a distinct morphological divergence and highly disparate distribution of the G. japonica-spengleri clade suggest that the ancestor of G. japonica entered into the Ryukyu Archipelago much earlier than those of M. mutica and C. flavomarginata. Taking the recently revised paleogeographical hypothesis of the Ryukyus into considerations, it is likely that the ancestral G. japonica has been isolated in the central Ryukyus since the Pliocene. On the other hand, populations of M. mutica and C. flavomarginata in the southem Ryukyus seem to have been isolated from their conspecific populations in Taiwan and southeastern continental China since the middle Pleistocene subsidence of land-bridges in these regions. Recent phylogenetic analyses strongly suggest the monophyly of Geoemyda, Cistoclemmys and Pyxidea. Of the species included in this clade, the three Geoemyda species exhibit much restricted and highly isolated distributions. By contrast, ranges of the Cistoclemmys and Pyxidea species are much broader, and include intervening areas of ranges of the three Geoemyda species. Such distributional patterns possibly reflect a much older origin and relict state of Geoemyda.
Added by: Sarina Wunderlich |