PHANEROZOIC SHALLOW-WATER DIVERSITY DRIVEN BY CHANGES IN SEA-LEVEL

Shallow water (< 50 m) marine diversity curves for the Phanerozoic, ba sed on area changes due to sea-level variation and continental movemen ts, are presented. It is shown that a change in the degree of endemism can alter diversity more than the effect of sea-level change, or chan ge in the number of faunal provinces. The pattern produced, for a cons tant degree of endemism, shows some rapid, but not periodic, falls in diversity. These occur in the Middle Cambrian, at the end of the Ordov ician, Devonian, Permian, Cretaceous and Eocene, and in the Messinian. There is no recurring single cause for these falls.