A prehistoric subfamily of canids (not canines) also known as "bone-crushing dogs". This subfamily was endemic to North America from the Oligocene to the Pliocene epoch and existed for about 33.5 million years. They were descendants of the basal canids, hesperocyoninae and includes the well-known epicyon. Genera:
More information:
https://en.wikipedia.org/wiki/Borophaginae