Morphological selectivity of the Permian-Triassic ammonoid mass extinction

Abstract Ammonoids suffered a diversity bottleneck during the Permian-Triassic mass extinction (PTME) and experienced rapid diversification in Early Triassic. However, kinds of ammonoids that were more likely to survive PTME fueled subsequent are still poorly known. We compiled comprehensive morphological data set used nonmetric multidimensional scaling method reveal impact on selectivity ammonoids. Our results show postextinction taxa occupied quite different morphospace when compared with pre-extinction assemblages. The survivors mainly smooth weakly ornamented forms, while late Permian species dominated by coarsely forms. Contrary previously recognized nonselective patterns, these suggest crisis. Newcomers Griesbachian compressed This shift from dominating Changhsingian possibly suggests an ecological turnover PTME.