ABSTRACT
The fossil record of Paleozoic crinoids, consisting of 883 generic ranges, was explored using several statistical techniques to identify patterns of faunal turnover and extinction. Three intervals of dominance were distinguished: an Ordovician interval characterized by the hybocrinid-disparid fauna, a Middle Paleozoic interval with an equitable, monobathrid-dominated fauna, and a Late Paleozoic, advanced cladid-dominated interval. Statistical analyses also revealed that in both instances the initiation of the turnover between the faunas occurred during times of intensified extinction.
