Hyaenodon

Hyaenodon Temporal range: Late Eocene to Early Miocene, 42–15.9 Ma PreЄ Є O S D C P T J K Pg N
H. horridus, Royal Ontario Museum.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Creodonta
Family:	†Hyaenodontidae
Genus:	†Hyaenodon
Type species
Hyaenodon leptorhynchus Laizer and Parieu, 1838
Species
List H. andrewsi H. brevirostris H. chunkhtensis H. crucians H. filholi H. gigas H. horridus H. incertus H. leptorhynchus H. matthewi H. megaloides H. microdon H. mongoliensis H. montanus H. mustelinus H. pilgrimi H. raineyi H. venturae H. vetus H. weilini H. yuanchensis

Hyaenodon ("hyena-tooth") is the type genus of Hyaenodontidae, a group of extinct carnivorous fossil mammals from Eurasia, North America and Africa, with species existing temporally from the Eocene until the middle Miocene, existing for approximately 26.1 million years.

The various species of Hyaenodon competed with each other and with other hyaenodont genera (including Sinopa, Dissopsalis and Hyainailurus), and played important roles as predators in ecological communities as late as the Miocene in Africa and Asia. Species of Hyaenodon have been shown to have successfully preyed on other large carnivores of their time, including a Nimravid ("false sabertooth cat"), Dinictis by analysis of tooth puncture marks on a fossil Dinictis skull in North Dakota.

Some species of this genus were among the largest terrestrial carnivorous mammals of their time; others were only of the size of a marten. Hyaenodon is one of the longest lived genera of Hyaenodontidae, 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).

Typical of early carnivorous mammals, individuals of Hyaenodon had a very massive skull but only a small brain. The skull is long with a narrow snout - much larger in relation to the length of the skull than in canine carnivores, for instance. The neck was shorter than the skull, while the body was long and robust and terminated in a long tail.

...
Wikipedia