OVERVIEW AND SIGNIFICANCE OF THE UNIVERSITY OF WYOMING PALEOZOIC AND MESOZOIC VERTEBRATE AND INVERTEBRATE FOSSIL COLLECTIONS

Wyoming has a rich paleontological record with specimens dating as far back as the Precambrian and extending through the Holocene. As such, the University of Wyoming (UW) Vertebrate Fossil Collection is an excellent resource for studying the paleobiology of the Rocky Mountain region because it contains around 9,500 fossil vertebrate specimens (~20% of the entire collections) from more than 50 different formations that date back to the Paleozoic and Mesozoic. The Paleozoic is represented primarily by the Beartooth Butte Fm. (42%) and the Water Canyon Fm. (13%), both of which are from the Devonian. Regarding the Mesozoic collections, most specimens are from the Cretaceous (94.5%), but material from the Triassic (0.5%) and, Jurassic (5%) are also available. Furthermore, most Mesozoic material was primarily collected in the following formations: the Lance Fm. (51%), the Mesaverde Fm. (19%), the Hell Creek Fm. (9%), Ferris Fm. (8%), the Morrison Fm. (3%) and Sundance Fm. (1.5%). In terms of taxonomic diversity, within the Paleozoic the top three classes are Agnatha (56%), Osteichtyes, and Placodermi (both 15 %). In the Triassic, the top three classes are Reptilia (50%), Osteichthyes (19 %), and Amphibia (17%). In the Jurassic, the top three classes are Reptilia (62%), Dinosauria (17%), and Osteichthyes (9 %). The UW Vertebrate Fossil collection is a valuable resource for studying Mesozoic mammals because nearly half of the Cretaceous vertebrate fossils belong to Class Mammalia. Reptilia (15.%) and Osteichthyes (11%) are also well represented in those collections. Lastly, the UW Vertebrate Fossil Collection houses several famous holotypes including: Megalneusaurus rex, Platypterygius americanus, Platypterygiu petersoni, Stegosaurus longispinus, Alphadon altaragos, and Meniscoessus seminoensi. Additionally, the museum maintains an Invertebrate Paleontology collection of over 13,000 specimens, with 42% collected from Wyoming. Within the invertebrate collection, the three best-represented phyla are Mollusca (42%), Brachiopoda (22%), and Arthropoda (10%). These specimens come primarily from the Cretaceous (19%), Permian (12%), and Devonian/Pennsylvanian (both 10%). Information about the Cenozoic holdings of the collection can be found at Kerr et al. in this session.