A New Brachiopod Fauna from the Early to Middle Permian of Southern Qinghai Province, Northwest China

摘要

A new brachiopod fauna is described from the Early and Middle Permian of Zadoi and Zhidoi counties, southern Qinghai (Changdu block), northwest China. This fauna includes 13 species in nine genera with Spinomarginifera concentrica n. sp. and Transennatia waterhousei n. sp. The Early to Middle Permian brachiopod fauna from southern Qinghai is very similar to the contemporary Cathaysian faunas of South China with which the new fauna shares 70 per cent of its species. On the other hand, the Qinghai brachiopods also demonstrate a significant link with the Permian brachiopod fauna of the Sino-Mongolian-Japanese Province in northeast China, as suggested by Marginifera septentrionalis and Attenuatella. In particular, the occurrence of the bipolar brachiopod genus Attenuatella suggests that southern Qinghai may have played an important role as a biogeographic stepping stone in the marine faunal interchanges between the northern and southern hemispheres during the Early and Middle Permian.