Hyaenodon

Hyaenodon ("hyaena-toothed") is an extinct genus of Hyaenodonts, a group of Creodonts. Some species of this genus were amongst the largest terrestrial carnivorous mammals of their time, others were only of the size of a marten. Hyaenodon was one of the latest genera of the Hyaenodonts and is known from the Late Eocene to Early Miocene. Remains of many species are known from North America, Europe, Asia and Africa (In 1993 42 species were distinguished).

Range and species

In North America the last Hyaenodon disappeared along with species like H. brevirostris in the late Oligocene. In Europe they had already vanished earlier in the Oligocene. From the Miocene in Africa there are three species (H. andrewsi, H. matthewi und H. pilgrimi) known, but none of these reached the dimensions of Asian species like H. gigas and H. weilini

Description

Typical of early carnivorous mammals, they had very massive skulls but only small brains. It had a long skull with a narrow snout - much larger in relation to the length of the skull than in canine carnivores, for instance. Its neck was shorter than its skull, while its body was long and robust and terminated in a long tail.

The average weight of adult or subadult H. horridus, the largest North American species, is estimated to about 40 kg and may not have exceeded 60 kg. H. gigas, the largest Hyaenodon species was much larger. H. crucians from the early Oligocene of North America is estimated to only 10 bis 25 kg. H. microdon and H. mustelinus from the late Eocene of North America were even smaller and weighed probably about 5 kg.