Degree Name

MS (Master of Science)



Date of Award


Committee Chair or Co-Chairs

Steven C. Wallace

Committee Members

James I. Mead, Blaine W. Schubert


Individuals of Tapirus polkensis from the Gray Fossil Site exhibit an excellent level of preservation. Intact skulls collected from the site were arranged in a rough age class system separated into 7 categories based on the teeth present and amount of dental wear. Such an eruption series is useful for general comparisons amongst the individual tapirs; however, the classes do not represent an age in years due to a lack of data on living tapirs. Consequently, it is possible that some age classes may contain several years of a tapirs life, or comparatively only a few months. In this study I placed ages on individuals of T. polkensis from the Gray Fossil Site based on age data taken from The Baird's Tapir Project of Costa Rica (Baird's Tapirs, T. bairdii) ranging from several months to 7 years in age. As eruption data is only useful for aging tapirs up to 7 years, this study also took dental wear into account for adult tapirs. After aging all possible individuals in the sample, the sample was compared to other studies on perissodactyl population structure. Interestingly, the T. polkensis sample is remarkably similar to modern populations of Diceros bicornis.

Document Type

Thesis - unrestricted


Copyright by the authors.