Deuterosaurus is an extinct genus of dinocephalian therapsids, one of the non-mammalian synapsids dominating the land during the late Paleozoic.

[11] Judging from related therapsids, the short but massive legs were held splayed, much like a modern crocodile.

While the large canines may indicate the ability to kill prey, the short legs and massive body would have made it unsuited as a long distance runner, and better suited to eating plants.

Then again, the possible stereoscopic vision again indicates an ambush style carnivore, and the rather blunt, cone-like post canine teeth can be interpreted both ways.

A remarkable thickening of the skull above the eyes indicates it may have engaged in head-butting, possibly in connection with mating or territorial disputes.