| Abstract: |
Palaeogeographic framework and habitat are summarised for known Siluro-Devonian vertebrate faunas from East Gondwana and various Asian terranes, including the highly endemic fauna from South China, and new discoveries on the Tarim block and Indochina terrane (Vietnam). New discoveries of Asian endemics outside the limits of the South China block provide evidence that it was already closely associated with other parts of Asia (North China, Tarim, Indochina) by the middle Palaeozoic. The interpretation of Asia as a collage of allochthonous terranes predicts that the degree of dissimilarity across terrane boundaries should increase with increasing geological age, but the currently known distribution pattern of Siluro-Devonian vertebrates in eastern Asia is more consistent with modern geography than with widely separated Palaeozoic Asia terranes. If these Asian terranes originated in Gondwana, then Palaeozoic vertebrate distributional data indicate at least pre-Silurian separation from Gondwana for South China, Tarim and probably the Indochina terrane, which the formed a composite terrane by Early Silurian time. The high endemism implies isolation of this composite terrane by significant marine barriers until the Middle Devonian, and a remote location off the Pacific margin of Gondwana is suggested. Continental connection between Gondwana and Asia in the latest Devonian is indicated by the occurrence in the Lachlan Foldbelt of eastern Australia of sinolepid antiarchs, a major group of placoderm fishes otherwise known only from Asia.
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