Chriacus is an extinct genus of placental mammals that lived in what is now North America during the Paleocene epoch and died out after the early Eocene.

The powerfully built limbs had flexible joints, especially the ankles, an adaptation that allows an animal to turn its hind feet behind it, like modern tree squirrels, in order to climb downward.

[2] Analysis of casts of the brain and inner ear from Chriacus pelvidens and C. baldwini suggest these animals depended more on their sense of smell than sight, may have been able to hear about as well as a modern aardvark, and were slow-moving to moderately agile.

Derived features of the inner ear were shared with fossils that are assigned to Euungulata (artiodactyls+perissodactyls), suggesting the genus may be close to the origin of ungulates,[3] though it is too different in form to be a direct ancestor.

Modern studies suggest the confusion is due to the fact that ungulates, carnivores, and creodonts are related groups, and flesh-eating lineages and adaptations evolved within each of them.