Anrewsarchus mongoliensis (pronounced ANN-drew-SARK-us), (Andrews + Greek ἀρχός, "ruler"), was a primitive, heavily-built, wolf-like, hoofed mammal that lived during the Eocene Epoch, roughly between 45 and 36 million years ago. It walked on four short legs and had a long body, a long tail, and feet with hoofed toes. It had a long snout with large, sharp teeth and flat cheek teeth that may have been used to crush bones. Because Andrewsarchus is only known from a skull and a few bones found, whether it was an active predator or merely a large scavenger is open to debate, as is its exact time range.