The case for sea-level change as a dominant causal factor in mass extinction of marine invertebrates

Abstract

A correlation between global marine regressions and mass extinctions has been recognized since the last century and received explicit formulation, in a model involving habitat-area restriction, by Newell in the 1960s. Since that time attempts to apply the species-area relation to the subject have proved somewhat controversial and promoters of other extinction models have called the generality of the regression-extinction relation into question. Here, a strong relation is shown to exist between times of global or regional sea-level change inferred from stratigraphic analysis, and times of high turnover of Phanerozoic marine invertebrates, involving both extinction and radiation; this is valid on a small and large scale. In many cases the most significant factor promoting extinction was apparently not regression but spreads of anoxic bottom water associated with the subsequent transgression. The sea-level-extinction relation cannot be properly understood without an adequate ecological model, and an attempt is made to formulate one in outline.