The taxonomic analysis of mass extinction intervals: An approach to problems of resolution as shown by Cretaceous ammonite genera (global) and species (Western Interior of the United States)

The application of diverse, yet basic, analytical metrics to high-resolution temporal and taxonomic data allows for precise documentation of ammonite origination, diversification, extinction, and turnover rates at the genus-substage and species-biozone level through mass extinction intervals. These dynamics are investigated for the entire Cretaceous for ammonites at the generic level, and during the highly dynamic Cenomanian-Turonian extinction interval at the specific level. A stepwise pattern of extinction can be interpreted from these data when investigated using high-resolution event stratigraphic techniques.