Ostracods after the end-Permian extinction in South China: insights into non-microbial survival

The taxonomy of ostracods from one deep-water, one shallow shelf and three paralic sections spanning the end-Permian extinction in South China (Guizhou and Yunnan) is summarized and discussed.We report on the occurrence of nine species, including mass occurrences of Hollinella panxiensis Wang, on the surface of these clastic Permian-Triassic transitional beds. The preservation of the material allows for the description of the central muscle scar field of Langdaia suboblonga Wang, which is the first observation of this character for the genus. These firstly described assemblages differ from those from post-extinction microbial deposits in being dominated by Palaeocopida. They illustrate survival without recovery after the end-Permian crisis, as none of the reported taxa participated in the subsequent Triassic diversification. We relate this phenomenon to clastic input and show that the patchy survival of benthic faunas following the crisis is an interplay between environments and adaptive potential. The persistence of Palaeocopida as a function of their depth distribution is discussed with the illustration of short-term survival of Hollinellidae in shallow areas, as opposed to the survival of Kirkbyidae in deep-marine waters until, at least, the Late Triassic.