Diversification, faunal change, and community replacement during the Ordovician radiations.

Abstract

The trilobite-dominated communities of the Cambrian were replaced by complex suspension-feeding communities dominated by brachiopods, bryozoans and pelmatozoans. Taxonomic diversity was increased 2- to 3-fold, both locally and globally. The Ordovician radiations represent a large-scale replacement rather than a simple transformation of Cambrian faunas and communities, resulting from large-scale interactions among taxonomic groups living in largely separate parts of the oceanic shelf environment.-P.J.Jarvis