Diplacodon

Diplacodon ("double-pointed tooth") is an extinct genus of brontothere. Diplacodon fossils have been found in North America and date to the Middle Eocene, during the Uintan land mammal age. Two Diplacodon species are recognized, the type species D. elatus from the Uinta Formation and the larger D. gigan from the Wiggins Formation.

Diplacodon ranged in size from about the size of a modern rhinoceros to slightly larger. Diplacodon and other contemporary North American brontotheres, such as Protitanotherium, were part of an early radiation of brontotheres in North America during the Middle Eocene and were descended from Central Asian ancestors. It is believed that Diplacodon and its close relatives ultimately gave rise to the larger brontotheres of the Brontotheriita infratribe, such as the more famous Megacerops. Similar to some other brontotheres, fossils assigned to D. elatus vary in the size and morphology of the teeth and horns. These variations have been argued to represent species-level, or even genus-level, differences, but recent revisions favor them as the result of sexual dimorphism and other individual variation. D. gigan is known from a single skull, making studies on intraspecific variation impossible in that species.