Constraining the biotic transitions across the end‐Ordovician mass extinction in South China: Bio‐ and chemostratigraphy of the Wulipo Formation in the Meitan area of northern Guizhou

Abstract

The richly fossiliferous succession of the Wulipo Formation in the Huangjiaba area near Meitan in northern Guizhou, SW China, represents one of the very rare records of shelly fauna across the Ordovician and Silurian transition worldwide. This area is therefore crucial for understanding the pattern and dynamics of the end‐Ordovician mass extinction (EOME). Historically, the Wulipo Formation was dated as middle Rhuddanian (early Silurian). However, its fauna shows a close affinity with Transitional Benthic Fauna 3 (TBF 3), now known to be confined within the late Hirnantian (latest Ordovician) in well‐constrained successions globally. Here we present for the first time, chemostratigraphic data from the Wulipo Formation which confirm the presence of the Hirnantian Isotope Carbon Excursion. A critical review of faunal evidence further indicates a late Hirnantian age for this formation, and thus the hitherto only known anomalous TBF 3 record documented from South China is convincingly redated. The important implication is that the substantial biotic recovery after the EOME commenced globally at the very beginning of the Silurian with an overall amelioration of physical conditions. The new findings also suggest a much wider distribution of postglacial warm‐water benthic faunas on the Yangtze Platform during the late Hirnantian than previously envisaged.

The latest Ordovician Hirnantian brachiopod faunas: New global insights

“…J o u r n a l P r e -p r o o f The brachiopods form the basal part of the Skelgill Beds in the Lake District, England characterized by the atrypid -Plectatrypa‖ flexuosa (Marr and Nicholson, 1888;Brenchley and Cocks, 1982;Cocks, 2008), the basal part of the Becscie Formation on Anticosti Island (Bergström and Goldman, 2019), lower part of the Hilliste Member (the Juru Stage), Estonia (Stott and Jin, 2007;Rubel, 2011), and the Wulipo Bed, Meitan, northeastern Guizhou, South China (Wang et al, 2020) were considered upper Hirnantian. But, more research on these brachiopod assemblages is required and are thus provisionally not included in the dataset for the Edgewood-Cathay Fauna.…”

Bedrock geological map predictions for Phanerozoic fossil occurrences

“…1A). One of the Asian polygons with a large number of matched fossil occurrences is a sedimentary polygon in southern China resolved only to the “Paleozoic”; it contains several fossil-rich, well-studied units, like the Cambrian Wangcun section in Hunan (e.g., Peng and Robison 2000), the Ordovician Meitan Formation in Guizhou (e.g., Wang et al 2020), the Silurian units of the Huaying Mountains in Sichuan (e.g., Wang et al 2013), the Devonian Lali section in Guangxi (e.g., Hou 1986; Zhang et al 2019), the Carboniferous Yashui section in Guizhou (e.g., Lin et al 2012), and the Permian Zhongzhai and Zhongying sections in Guizhou (e.g., Zhang and He 2008; Wu et al 2019). These strata range from Cambrian to Permian in time (between 541 and 251.9 Ma) and are located in various Chinese provinces across a considerably large region.…”