Xinpusaurus Revisited: A Carnian Triassic Thalattosaur From China

On the morphoplogy and taxonomic status of Xinpusaurus kohi JIANG et al., 2004 (Diapsida: Thalattosauria) from the Upper Triassic of China

Author:

Maisch

Abstract:

Additional preparation has revealed new information on the cranium and the vertebral column of the type and only specimen of Xinpusaurus kohi JIANG et al., 2004, a thalattosaur from the Upper Triassic Xiaowa Formation of Guanling County (Guizhou, south-western China). The new data allow to supplement existing descriptions and to decide on some controversial points raised in recent discussions. Although the skeleton is almost complete, there is some reconstruction, which makes the low presacral vertebral number and the narrow proximal end of the femur, originally regarded as diagnostic characters, doubtful. All other diagnostic characters of the species are valid. Comparison to another thalattosaur species from the Xiaowa Formation, Xinpusaurus bamaolinensis, shows great similarities, but is limited due to its insufficient description. Hence, it cannot be excluded that X. kohi is a junior subjective synonym of X. bamaolinensis. However, the recent claim that X. kohi and X. bamaolinensis are synonyms of X. suni, the type species of the genus, is not supported by the new data. The description of X. bamaolinensis leaves many points unclear. Pending a re-description of that specimen that may allow for a more meaningful comparison, X. kohi should be allowed to stand.