LYSTROSAURS OF XINJIANG, CHINA

<正> Since the first report on Chinese lystrosaurs made by Yuan and Young in 1934, abundant material has been collected from the Early Triassic of Jiuchaiyuan Formation of Jimusar (Fuyuan), Junggar basin and Taoshuyuan, Turpan basin. Up to now 7 species of Lystrosaurus——L. broomi, L. hedini, L. weidcnreichi, L. youngi, L. robustus, L. latifrons and L. shichanggouensis, have been erected in China. All the species were described based on almost complete skulls, except L. weidenreichi, which was on some materials of postcranial skeleton. It was thought generally that L. broomi and L. youngi are closely related to the South African L. murrayi and L. curvatus respectively. Furthermore, the two Chinese species were considered as synonymous with their counterparts of South Africa by Colbert in 1974, when he revised this genus. The characters of the Chinese lystrosaurs, however, appeared to give no support to Colbert's suggestion. A comprehensive study of the Chinese lystrosaurs based on the type specimens and the additional materials, and the revised diagnoses. for 4 species are given in the present paper.