Fish from the Upper Devonian of the Shan-Thai terrane indicate proximity to east Gondwana and south China terranes

We report the first discovery of abundant Devonian vertebrates from Thailand. An unusual form of coronodontid shark tooth with six equal-sized cusps occurs only in the Upper Devonian of Thailand (Shan-Thai terrane) and south China, and a new species of Phoebodus is reported that occurs elsewhere only in south China and Australia (east Gondwana terrane). The occurrence of the chondrichthyan Harpagodens (Thrinacodus) ferox Turner 1982 in the Late Devonian of Thailand, Australia, and south China predates the appearance of this species in Euramerica (early Carboniferous). These data suggest Late Devonian proximity of the Shan-Thai, south China, and east Gondwana terranes, and is in accord with recent paleomagnetic data. -Authors