The Shanita fauna (Permian foraminifera) from Baoshan area, western Yunnan Province, China

Abstract

Studies in the past decade have proven the Shanita fauna to be an excellent marker of the northern peri-Gondwana tectonic blocks. Thus, a study of the Shanita fauna from the Baoshan area in western Yunnan Province, China, could provide pivotal paleontological evidence for the paleogeographic reconstruction of the Baoshan block. We systematically analyzed the composition and the age of the Shanita fauna from the Permian Da’aozi Formation in Woniusi Section of the Baoshan area. Results suggested that the characteristic genera Shanita and Hemigordiopsis in this fauna comprised eight species (including two new species), and ten genera of other nonfusulinid foraminifera were also recognized from this fauna. Further comparative study showed that the Shanita fauna from the Baoshan area were probably late Maokouan (Lengwuan) to Wuchiapingian in age. In general composition, this fauna is comparable to those Shanita faunas from Shan State of Burma, Peninsular Thailand, and Nagri of Tibet, China. However, the relatively low generic diversity and occurrence of some endemic species, as well as the absence of fusulinids, indicate certain regional features of the Shanita fauna from the Baoshan area.