Extinct ungulate groups include Ancylopoda and Condylarths.
In addition to hooves, ungulates developed reduced canine teeth, bunodont molars (molars with low, rounded cusps), and an astragalus (one of the ankle bones at the end of the lower leg) with a short, robust head. Ungulates diversified rapidly in the Eocene, but are thought to date back perhaps as far as the Late Cretaceous. Most ungulates are herbivorous, but a few are omnivorous or predaceous (e.g. some whales).