Emmalynn May ’23 Looks at the Beloit College La Brea Tar Pit Fossil Collection
Emmalynn May is a Geology and Environmental Biology major working with thesis advisor Jay Zambito. She is looking at the taxonomy and taphonomy of Beloit College’s La Brea Tar Pit fossil collection.
The fossils found at the La Brea Tar Pits, in Los Angeles County, CA, are world famous for their preservation and importance for understanding Pleistocene vertebrate ecosystems. The tar pits were open at different times (between 11-50k years ago, during the Pleistocene Epoch) and contain specimens that became trapped while each was pit active. Previous studies have shown a distortion between the typical mammalian fauna ratio of predator-to-prey in the La Brea faunas, with the overwhelming number of La Brea specimens belonging to predators like the dire wolf (Aenocyon dirus) and Saber-toothed cat (Smilodon fatalis). Beloit College’s La Brea specimen collection is primarily unidentified and the age of the fossils are unknown. It was brought to the college by Ira Buell in 1910 after he personally excavated them. Some of the specimens have his original identification cards, however, the vast majority do not. To better understand if the collection reflects what is known about previously studied tar pits and Pleistocene ecosystems generally, my thesis will focus on taxonomy and taphonomy as well as the predator-to-prey ratio.
Fossils are being identified using a plethora of data ranging from previous identification cards, museum photographs, and databases of museum collections. Preliminary results show that several of the previous identifications are incorrect, not all fossils are identifiable, and many are broken or altered. Rare fossils show features interpreted as gnaw marks that may be associated with predation or scavenging. This study will give a better understanding of how the predator-to-prey ratio and taphonomy of the Beloit College collection compares to other La Brea and Pleistocene assemblages.