Lower jaw of a bone-crushing dog

Lower jaw of a bone-crushing dog

NMMNH P-25264

Bone-crushing dog, hyena-like dog

Canine

Cuchillo Negro creek, near Truth or Consequences, Sierra County

Pliocene, about 3 million years ago

Lower jaw with most of the teeth

The large, Pliocene, bone-crushing dog Borophagus was the last or youngest member of the borophagines, an extinct group of the dog family (Canidae). The borophagine dogs are unique to North America and included many large species that lived a scavenging existence, much like Old World hyaenas, eating carcasses of large mammals and using their powerful skulls, jaws, and teeth to crush bones to obtain the nutritious marrow. The New World bone-crushing dogs and the Old World hyenas are an excellent example of convergent evolution, in which two unrelated families of carnivores evolved similar teeth, body form, and life style. Both bone-crushing dogs and hyenas have massive skulls, powerful jaws, large blunt teeth, and robust front limbs, all of which are adaptations for scavenging carcasses and crushing bones of large mammals.