The use of shell beds as a tool for investigating ecological changes across mass extinction intervals

Abstract

INTRODUCTION Beginning with Sepkoski’s work in the early 1980’s, various iterations of diversity compilations have been published illustrating the taxonomic devastation of mass extinctions (e.g. Alroy et al., 2008; Sepkoski, 1981). Often, these diversity changes are assumed to correlate with (or even be the root cause of) broad ecological changes. For example, the taxonomic devastation of brachiopods at the end-Permian extinction in contrast with bivalves, which were relatively unscathed, led Gould and Calloway (1980) to conclude that the high species turnover triggered an ecological revolution in benthic marine communities. With a few notable exceptions (e.g. Jablonski, 2008) few authors have considered that major turnovers in ecology may be more complex, protracted events and relatively few studies have examined ecological changes across mass extinction intervals independently of diversity changes. It is important to evaluate them separately because, although taxonomic diversity is a reflection of ecological processes, it cannot be