Microphytoplankton diversity curves of the Chinese Ordovician

Abstract

Abstract Following the publication of a regional diversity curve of the Ordovician organic-walled microphytoplankton (acritarchs) from the Yangtze Platform at the species level [Servais et al., 2004], a diversity curve for China is here presented using all literature data at the generic level. The Chinese curve is a compilation of three separate curves from the three major continental blocks that constituted China in the Ordovician: South China (including the Yangtze Platform), Tarim and North China. The diversity changes can partly be related to sea level changes, both at a regional (South Chinese sea level curve) and at a global level (global curve). The totalised curve for all Chinese localities indicates peaks in diversity that apparently correspond to three sea level highstands at a global level at the early-middle Ordovician boundary (middle “Arenigian”), at the Sandbian-Katian boundary (middle “Caradocian”) and during the Upper Katian (pre-Hirnantian “Ashgillian”) Boda Event [Fortey and Cocks, 2005].