Borophagus

Borophagus ("gluttonous eater") is an extinct genus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Zanclean stage of the Pliocene epoch 23.3—3.6 Mya. Borophagus existed for approximately 19.7 million years

Evolution
Borophagus, like other borophagines, are loosely known as "bone-crushing" or "hyena-like" dogs. Though not the most massive borophagine by size or weight, it had a more highly evolved capacity to crunch bone than earlier, larger genera such as Epicyon, which seems to be an evolutionary trend of the group (Turner, 2004). During the Pliocene epoch, Borophagus began being displaced by Canis genera such as Canis edwardii and later by Canis dirus. Early species of Borophagus were placed in the genus Osteoborus until recently, but the genera are now considered synonyms.

Canid competitors
Borophagus was one of the last of the Borophaginae and would have shared its North American habitat with other canids: Epicyon ((20.6—5.330 Ma), Paratomarctus (16.3—5.3 Ma), Carpocyon (20.4—3.9 Ma), Aelurodon (23.03—4.9 Ma), and the first emerging wolf, Canis lepophagus appearing 10.3 Ma.