Size Variation of Foraminifers during the Permian-Triassic Transition at Meishan Section, South China

摘要

INTRODUCTION The most severe disaster event in the Phanerozoic history of earth's life happened in the Permian-Triassic (P-T) transition, which witnessed the greatest extinction event at the end of the Permian and the delayed biotic recovery in the entire Early Triassic (Tong et al., 2007; Erwin, 2006; Payne et al., 2004). Organisms with heavy calcification and limited elaboration of circulatory and respiratory systems (e.g. articulates, echinoderms, bryozoans, cnidarians) were most severely affected, whereas those with lightly calcified or uncalcified skeletons and more active control of circulation, elaborated structures for gas exchange (e.g. mollusks, arthropods, chordates) survived in much higher proportions (Knoll et al., 1996).