Faculty Advisor: Renee Love
The Taxonomy and Phylogenetic Implications of a Mammoth Hybrid from Southeastern Idaho
During the Pleistocene to Holocene transition, three mammoth species lived in North America: the Woolly, Columbian, and recently discovered hybrid of the two, Jeffersonian Mammoth. Genetic studies provide insight into mammoth speciation, but a lack of testable genetic material prevents this method from being used broadly. Without extracting DNA, molar measurements are used to determine species. There is uncertainty surrounding mammoth taxonomy when it is based solely on molar measurements, however, and can display a degree of overlap between species. In this study, ~75% of a mammoth skeleton was excavated near Soda Springs, Idaho was cataloged, radiocarbon AMS dated, and mammoth species was preliminarily determined.
The dating produced an age of 11,700 +/- 40 years, which was ~200 years before complete mammoth extinction on mainland North America. After taxonomically describing the mammoth, molar measurements suggest it is a Jeffersonian Mammoth hybrid, but we are in the process of getting genetic testing to refute or confirm this. The mammoth is estimated to be 15-18 years old and genetic results will aid in understanding how ontogeny affected these taxonomic descriptions. Future work involves measuring 77 different characteristics of mammoth skulls, mandibles, molars, and tusks from digital and physical specimens to compare this skeleton with published images of skulls associated with type specimens that lived during the same time across North America. This study serves to erect new taxonomic criteria by which a mammoth’s skull is indicative of its species. Applying this framework to the most well understood mammoths in North America, further studies into the taxonomy of mammoth species may aid in discerning their evolutionary relationships. Implications of this study may indicate that mammoth species were interbreeding in Idaho, and that a possible refugium environment existed.
Funding: GSA Graduate Student Research Grant