Brontotherium
Brontotherium is a genus of brontothere that lived during the Eocene period. Male brontotheres have been observed very differently with females.
Other inhabitants
Brontotherium co-existed with Embolotherium, Indricotherium, Hyaenodon, Chalicotherium and Paraceratherium, as well as ocean-dwelling creatures like Dorudon, Basilosaurus and Otodus.
Etymology
Brontotherium comes from Ancient Greek βροντή (brontḗ), meaning "thunder", and θηρίον (theríon), meaning "beast".