Duchesneodus
Duchesneodus is a large brontothere endemic to North America. It lived during the Late Eocene 40.4—37.2 mya, existing for approximately. The skeletal characteristic of the mammal was defined by the dome size that was sexually in two distinct forms. The females had a lower but prominent dome while the males had larger domes. Several species of Duchesneodus have been named historically, though only one is recognized as valid today, D. uintensis.