Hyaenodon

Hyaenodon [Brule Formation, Pennington County, South Dakota]

The genus Hyaenodon contained carnivorous mammals that lived from the Eocene Epoch 42 million years ago until extinction during the Oligocene Epoch 25 million years ago. There so far are records of at least 30 species with fossils found in Asia, Africa, Europe, and North America. Hyaenodon means "hyena-toothed" as these animal had large, sharp teeth for their carnivorous diet.

Teeth of the Hyaenodon

During their existence, Hyaenodon was a dominant predator. The species ranged in size from small and fox-like to others as large as rhinos. It is believed the smaller species hunted in packs, likely at night, whereas the larger species likely hunted alone. Extinction of the order Creodonta, of which Hyaenodon belongs, possibly came from competition with Carnivora, the order most carnivores belong to in modern times.

From the newest fossil collection at the Heard Natural Science Museum and Wildlife Sanctuary.