Borophagus

Skull of Borophagus

Florida, Mexico, Texas

Borophagus (Greek: boros - voracious, phago - eat) is an extinct genus of the family of dogs ( Canidae ). It is eponymous for the subfamily of Borophaginae and life was limited to North America.

Borophagus reached a body weight of about 20-40 kg and resembled a hyena. However, lacking the typical for today's hyenas sloping topline. The genus represents the last member of Borophaginae, a special sub family of dogs. Borophagus likely to have well- developed from Epicyon and first appeared in the middle Miocene epoch, about 12 million years ago in the west of the North American continent. Even more than in Epicyon the fourth mandibular premolars were developed, which led to an extreme crushing scissor bite. Both genera are likely similar to today's large hyenas have been adapted to the break-up of large bones. As a further adaptation to this niche of the lower jaw of these forms was extremely strong and highly arched brow. Ever since the upper Miocene epoch, about 9 million years Borophagus was widespread across the continent. The last species of the genus is represented by Borophagus diversidens. This reached a shoulder height of about 60 cm. Only at the beginning of the Pleistocene, about 2 million years ago the big dog disappeared and with it the subfamily of Borophaginae. The last representatives of the genus had to compete with the slim hyena Chasmaporthetes that had migrated from Eurasia to North America in the Pliocene. The niche of the big dogs, however, was occupied during the Pleistocene species of the genus Canis. The members of the genus Canis were at times of Borophagus all still relatively small to Canis armbrusteri with around 1.5 million years ago for the first time a great form of wolf genus in the fossil record of North America occurred. From this type of huge Canis dirus, represented the largest species of dogs of the late Pleistocene developed in the Middle Pleistocene

The following types are known:

• Borophagus littoralis (late Miocene )
• Borophagus Pugnator (late Miocene )
• Borophagus orc (late Miocene )
• Borophagus parvus (late Miocene )
• Borophagus secundus (late Miocene )
• Borophagus hilli (late Miocene )
• Borophagus dudleyi (late Miocene )
• Borophagus diversidens ( Pliocene )