Earth and Planetary Sciences ETDs

Publication Date

Summer 8-1-2023


Paleoecological analyses of six shallow marine bivalves were conducted to test the Abundant Center Hypothesis using data from the fossil record of the Pleistocene through modern day. This hypothesis predicts the highest abundance of a species is at the center of the geographic or environmental range, decreasing toward the edges. In geographic space, distances to a centerline within a geographic range were variably correlated with population abundances, and some species displayed a sharp drop-off in abundance as distance increased. In environmental space, bivalve species showed moderate correlations between abundance and centrality when measured using cumulative data across the last 2.8 Ma. Shorter time bins across that duration show no consistent patterns, potentially indicative of an abundance-centrality pattern apparent only in the species’ fundamental niche, which is best measured cumulatively over geologic time. These results suggest caution should be taken when interpreting modeled environmental preferences, particularly over short durations.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Corinne Myers

Second Committee Member

Jason Moore

Third Committee Member

Louis Scuderi




Abundant Center Hypothesis, biogeography, paleoecology, marine invertebrates, Atlantic Coastal Plain, Gulf Coastal Plain

Document Type


Included in

Paleobiology Commons