ammonites
Brontops brachycephalus Osborn 1902 (brontothere)

Mammalia - Perissodactyla - Brontotheriidae

Alternative combination: Megacerops brachycephalus

Full reference: H. F. Osborn. 1902. The four phyla of Oligocene titanotheres. Bulletin of the American Museum of Natural History 16(8):91-109

Belongs to Brontops according to B. J. Mader 1998

Sister taxa: Brontops amplus, Brontops bicornutus, Brontops dispar, Brontops robustus, Brontops selwynianus, Brontops tyleri

Type specimen: Its type locality is Quinn Draw (Lower Titanotherium Beds), which is in a Chadronian terrestrial horizon in the Chadron Formation of South Dakota

Ecology: ground dwelling browser

Average measurements (in mm): M1 50.0 x 50.1, M2 66.2 x 60.9, M3 66.5 x 62.7