Paleogene Mammal Dispersal and Biogeography

Members of the Beard Lab collecting Paleocene mammals in the Bison Basin of central Wyoming. Current research focuses on whether ancient river drainages impacted mammalian biogeography and evolution by functioning as barriers to dispersal.

The evolution of North American mammals during the early Cenozoic is best documented in the Bighorn Basin of northern Wyoming, where decades of research and thousands of fossil mammals have created a “gold standard” that serves as a baseline for assessing the fossil record in other parts of the United States. Members of the Beard Lab are exploring spatial and temporal heterogeneity in the fossil record of North America by looking at understudied sites in southern Wyoming and Texas. Anachronistic assemblages of taxa frequently occur in these sites, because of the precocious appearance of certain clades and the delayed extinction of others.

A tiny carpolestid jaw preserving p4-m3 from the West End locality in the Bison Basin. Carpolestids are incredibly rare in the Bison Basin, and this remains the only specimen of a carpolestid known from this classic Tiffanian locality.