Darriwilian Saucrorthis Fauna: Implications for the great Ordovician Biodiversification event (GOBE)

Abstract

The Saucrorthis Fauna is a brachiopod-dominated shelly fauna developed in relatively deeper-water benthic regimes of a few peri-Gondwana terranes (e.g. northern Iran) and palaeoplates (South China and Sibumasu) during the Darriwilian (late Middle Ordovician). It has its longest geological range, widest palaeogeographic distribution, most abundant and diversified brachiopod taxonomic composition and most complex palaeoecological differentiation in South China, where it concentrated in the centre of the Upper Yangtze Platform. The generally low similarity coefficients (< 0.3) between any two representatives of the Saucrorthis Fauna firmly support a statement about the Great Ordovician Biodiversification Event (GOBE) that strong endemism or provincialism made a great contribution to the second pulse of the Ordovician brachiopod radiation in South China, which might also be true for the international trend.