Date of Graduation


Document Type


Degree Name

Master of Arts in Anthropology (MA)

Degree Level





Amelia Villaseñor

Committee Member

John Samuelsen

Second Committee Member

Celina Suarez

Third Committee Member

Peter Ungar


Bison, Extinction, Mammoth, Migration, Paleoecology, Strontium


During the Late Pleistocene (LP; past 130,000 years), over two-thirds of large mammal (>45kg) species went extinct globally. While the role of humans is hotly debated, the effect of these extinctions is growing clearer; the extinctions resulted in widespread and lasting faunal community reorganization. However, the impact of these extinctions on dietary and migratory behavior within faunal communities is unknown. Our study examines the impact of the megafaunal extinctions on the dietary and migratory behavior of surviving Bison individuals in Texas using carbon, oxygen, and strontium isotopes. Strontium isotopes are incorporated into mammalian enamel during their tooth development and varies as these organisms travel to areas with new bedrock. To capture movement within an individual in the fossil record, serially sampling a single tooth can reveal the movements of an individual across space. Here, we examine the carbon, oxygen, and strontium isotopes from the enamel of two ubiquitous Pleistocene genera (Bison and Mammuthus) before the megafaunal extinctions. We preferentially sampled sites older than the commonly cited (12 Ka) date for widespread human occupation in North America. We also sampled Bison that survived the megafaunal extinction to compare migratory patterns before and after the extinction. This study thus presents high-resolution, serially sampled stable isotope data on bison (n=10) and mammoths (n=5) collected from five LP sites, dating from 33 to 11 Ka, in central Texas. Preliminary strontium isotope data suggest that Mammuthus has larger home ranges in Texas (>100km) than modern savannah elephants (30–50km). Our data will reveal important information about the effects of megafaunal extinction on migratory patterns through time. Given the small samples sizes of this study, additional research is needed to refine our understanding of the mechanisms causing this spatial and temporal variation and its relevance to other taxa.