Research Training Program

Jonathan Marcot
University of Arizona
Tucson, Arizona

Elizabeth Valiulis, Ph.D.
Project Advisor
Department of Paleobiology

"Every goal was met and every expectation exceeded."

Bellerophontoidea's Last Stand: A Phylogenetic and Paleobiogeographical Approach

The Superfamily Bellerophontoidea is a large, but problematic group of gastropod molluscs. Despite extensive distribution during most of the Paleozoic, it suffers greatly immediately before and during the end-Permian mass extinction, finally becoming entirely extinct in the Triassic. Their patterns of diversity and distribution during the late Permian and early Triassic suggest a gradual, intensifying extinction pressure in the late Paleozoic. A phylogenetic context enhances these patterns. The cladistic approach also suggests some flaws in the current taxonomy of the Bellerophontoidea.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates program, Award Number BIR-9300225.