Quantitative insights into the community shifts of bivalves following the end-Permian mass extinction: New evidences from Guizhou, southwestern China

Abstract

The Early Triassic provides crucial insights into the initial biotic recovery following the end-Permian mass extinction, the most severe biotic catastrophe during the Phanerozoic. This study presents the newly compiled bivalve data from the Lower Triassic of the Liuzhi and Bozhou sections. Based on multiple quantitative methods, five distinct ecological associations are recognized. The bivalve associations exhibit high level of spatial homogeneity with temporally equivalent bivalve faunas in taxonomic composition. The rapid diversification of cosmopolitan genus Claraia contributes to the significantly higher species diversity observed in Claraia-dominated associations. Despite the taxonomic changes, the trophic structure is not substantially altered, indicating the high resilience of bivalves to the complex abiotic and biotic conditions with strong capacity of niche filling. The high faunal homogeneity with contemporary communities and relatively simple trophic structure of the post-extinction bivalve associations identified herein are indicative of limited biotic recovery of level-bottom community in the studied sections.