Abstract:
The age and sedimentary environment of the Silurian “Lower Red Beds” (LRBs), which occur widely in South China, have long been controversial because of the scarcity of index fossils. Recently, these beds have been dated by trilobites as middle-late Aeronian to early Telychian inage. Here, we report abundant brachiopods from the LRBs in Wuhan, Middle Yangtze Region,
including atrypides (Meifodia hunanensis, Zygospiraella sp. 1, Zygospiraella sp. 2 and Nalivkinia? sp.), spiriferides (Striispirifer acuminiplicatus, Striispirifer? sp.), strophomenides (Eostropheodonta? sp. and Katastrophomena modesta), and linguliformeans (Anomaloglossa? sp. and Orbiculoidea? sp.). Most of these are common in the Leijiatun, Xiangshuyuan, Shihniulan, Niuchang, Lojoping, and Shamao formations in the Upper Yangtze Region. The discovery of brachiopods from the LRBs in Wuhan not only enrich the biodiversity of the LRBs in the Yangtze Region, where Meifodia, Zygospiraella, Katastrophomena and Eostropheodonta are first found in the LRBs, but also expand the paleogeographical distribution of brachiopods to Middle Lower Yangtze Region that first radiated after the end-Ordovician extinction. In addition, this brachiopod fauna also provides important implications for the sedimentary environment of LRBs during the Llandovery, which is usually developed in the nearshore shallow-water (BA1-2), althought this paper extends to the deeper parts of the shallow-marine (BA3-4).
