OVERVIEW AND SIGNIFICANCE OF THE UNIVERISTY OF WYOMING CENOZOIC VERTEBRATE FOSSIL COLLECTION

Wyoming has a rich Cenozoic fossil record due to several highly fossiliferous formations outcropping within the state’s Laramide basins and High Plains. As such, the University of Wyoming (UW) Vertebrate Paleontology Collections has been and continues to be an excellent resource for studying the geological and biological history of the Rocky Mountain region, particularly for the Cenozoic Era. Here we summarize the key features of the University of Wyoming Cenozoic Vertebrate Collection, emphasize the significance of the fossils housed therein, and encourage researchers to visit.

Cenozoic specimens account for nearly 75% (n= 35,600) of the Vertebrate Fossil Collection, and of them, most originate from Paleocene and Eocene aged rock units (37% and 41%, respectively) including the Fort Union Fm. (19%), the Willwood Fm. (17%), and the Hanna Fm. (10%). In terms of taxonomic diversity, mammalian specimens are by far the most dominant class representing 86% of the collections with the primary orders being Condylarthra (15%), Rodentia (11%), Primates (11%), and Multituberculata (10%). When considering each epoch, there’s a notable shift from the Paleocene to the Eocene taxa when Multitubuerculata, Primates, Condylarthra and Perissocatyla fossils give way to Rodentia, Artiodacytla, Perissodactyla, and Carnivora in the later epochs. The most common genera found within the UW Cenozoic Fossil Collection are Hyopsodus (n=1,453), Hyracotherium (n=1,057), Ptilodus (n=1,026), and Plesiadapis (n=459). Reptiles (8%), bony fish (3%), birds (2%), and cartilaginous fish (1%) are also represented within the UW Cenozoic Fossil Collection.

Although other institutions house larger Cenozoic vertebrate fossil collections, the UW Vertebrate Fossil Collection is remarkable because it includes a significant portion of the country’s Paleocene vertebrate fossils. Furthermore, the collection houses over 40 mammalian holotypes, includes localities covering important climate transitions such as the Paleocene/Eocene Thermal Maximum. The collection additionally offers high-fidelity snapshots into past ecosystems like the Eocene Green River Lagerstatten or the Pleistocene Natural Trap Cave deposits. Information about the Paleozoic and Mesozoic holdings of the collection can be found at Haupt et al. in this session