Paleogene Mammal Dispersal and Biogeography

A map showing the evolution of Paleogene mammals against the dynamic backdrop of climatic and tectonic changes.

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.

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.

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.

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.

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.

Recent Publications

Rust, K., Ni, X., Tietjen, K., and Beard, K.C. 2023. Phylogeny and paleobiogeography of the enigmatic North American primate Ekgmowechashala illuminated by new fossils from Nebraska (USA) and Guangxi Zhuang Autonomous Region (China). Journal of Human Evolution185: 103452. doi:10.1016/j.jhevol.2023.103452

Miller, K., Tietjen, K., and Beard, K.C. 2023. Basal Primatomorpha colonized Ellesmere Island (Arctic Canada) during the hyperthermal conditions of the early Eocene climatic optimum. PLoS ONE18: e0280114. doi:10.1371/journal.pone.0280114

Jones, M.F., Li, Q., Ni, X., and Beard, K.C. 2021. The earliest Asian bats (Mammalia: Chiroptera) address major gaps in bat evolution. Biology Letters 17: 20210185. doi:10.1098/rsbl.2021.0185

Mattingly, S.G., Beard, K.C., Coster, P.M.C., Salem, M.J., Chaimanee, Y., and Jaeger, J.-J. 2020. A new carnivoraform from the early Oligocene of Libya: Oldest known record of Carnivoramorpha in Africa. Journal of African Earth Sciences172: 103994. doi:10.1016/j.jafrearsci.2020.1039942016

Beard, K.C. 2016. Out of Asia: anthropoid origins and the colonization of Africa. Annual Review of Anthropology45: 199-213. doi:10.1146/annurev-anthro-102215-1000192015

Coster, P.M.C., Beard, K.C., Salem, M.J., Chaimanee, Y., Brunet, M., and Jaeger, J.-J. 2015. A new early Oligocene mammal fauna from the Sirt Basin, central Libya: biostratigraphic and paleobiogeographic implications. Journal of African Earth Sciences 104: 43-55.