An endemic brachiopod faunule from the Aeronian (early Silurian) of South China: palaeobiogeographical and palaeoecological implications

Abstract

After the Late Ordovician mass extinction, brachiopods recovered and re-radiated during the Aeronian age of the early Silurian. However, a drastic turnover of Ordovician-type to Silurian-type faunas took place. In South China, Aeronian brachiopod faunas are rarely reported and typically of low diversity. Here, we describe an endemic brachiopod faunule from the middle Xiangshuyuan Formation (middle Aeronian) of Yinjiang in northern Guizhou Province, South China. The fossils include five endemic species assigned to five genera. With the exception of Zygospiraella, at least three of these genera are also endemic. The diagnoses of Qianomena and Sinokulumbella are revised based on new specimens. The palaeobiogeographical and palaeoecological implications of the faunule are discussed and interpreted as products of climatic warming and increased habitat heterogeneity during the Aeronian. Bing Huang [ bhuang@nigpas.ac.cn ] and Jia-yu Rong [jyrong@nigpas.ac.cn] , State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China; Di Chen [dichen@nigpas.ac.cn ] China University of Chinese Academy of Sciences, Beijing 100049, China.