Pentacosmodon is a mammal genus from the Paleocene of North America, so it lived somewhat after the "age of the dinosaurs". It was a member of the extinct order Multituberculata. It's within the suborder Cimolodonta and family Microcosmodontidae.The genus Pentacosmodon, named by Jepsen in 1940, is known from the species Pentacosmodon pronus.