Drivers of Selective Mass Extinction: Insight from Integrated Paleontological and Geochemical Records

University Of Connecticut, Storrs CT

Investigators

Abstract

Environmental changes in the modern world threaten many species with extinction. Understanding how similar disruptions drove extinction in Earth's past provides essential context for understanding current risks to the biosphere. This project focuses on the Late Devonian mass extinction, one of the "Big 5" mass extinctions in Earth's history, which occurred approximately 372 million years ago. It will address the following questions: 1) How did environmental conditions change during this extinction? 2) What kinds of animals survived the extinction and what kinds died? 3) What features or traits of these organisms promoted survival versus extinction? The project will combine information from multiple spatial scales, including extensive fossil collections from Late Devonian-aged rocks in upstate New York and Pennsylvania and 'Big data' mined from global, community-wide databases. The project includes outreach through local museums, including public lectures on extinction and the development of new hands-on activities for use at a local children's museum. The field-based component of the project will focus on stratigraphic ranges of brachiopod and coral species in the upper Frasnian and lower Famennian of the Appalachian Basin, organic carbon isotopes through measured stratigraphic sections, and proxies for oxygenation, including fossil content and trace metals. The global component will draw on the temporal, paleoenvironmental, and paleolatitudinal ranges of genera in the Paleobiology Database and other databases; new Late Devonian collections will be added to improve data coverage. Leading proposed causes of extinction include global cooling and ocean anoxia. At both the regional and global scales, selectivity of extinction with respect to these factors will be evaluated using latitudinal range as a proxy for temperature tolerance and paleoenvironmental preference (depth preference and range) as a proxy for vulnerability to oxygen depletion.