Collaborative Research: Patterns of Diversity and Faunal Turnover at a Late Cambrian Trilobite Extinction Event: Testing for Phylogenetic, Stratigraphic and Environmental Biases

University Of Iowa, Iowa City IA

Investigators

Abstract

Collaborative Research: Patterns of diversity and faunal turnover at a Late Cambrian trilobite extinction event: testing for stratigraphic, environmental and phylogenetic biases Stephen Westrop, Univ. Oklahoma EAR-0309092 Jonathan Adrain, Univ. Iowa EAR-0308685 ABSTRACT One of the great challenges of paleontology is to understand mass extinctions in the fossil record - geologically brief episodes in which ecosystems collapsed and biotas were decimated. Paleontologists are becoming increasingly aware that various biases related to physical processes or errors in the classification of fossils can distort the pattern of extinction, or even create the illusion of extinction where none exists. For example, sea level changes influence our perception of extinction events through erosion or non-preservation of fossils in critical intervals of the rock record. Such biases must be stripped away before we can get an accurate estimate of the magnitude of extinction and assess the processes that might be responsible. This project evaluates biases and examines potential extinction mechanisms in the record of Cambrian trilobites, a group of arthropods that were among the dominant animals in marine environments about half-a-billion years ago. The results are likely to throw new light on other mass extinction events, particularly by providing a better understanding of the impact of various biases on our recognition of such events. The project also has a significant educational component through the participation of graduate students at the University of Oklahoma and the University of Iowa.