Hyaenodon
Skull of Hyaenodon cayluxi in the Paris Muséum national d' Histoire naturelle
- North America
- Asia
- Africa
Hyaenodon is a genus of extinct mammalian order Creodonta or Urraubtiere, it belongs to the family within which the Hyaenodontidae. The genus was one of the latest genera of this family and is mainly from the late Eocene and early Oligocene, but also from the Late Oligocene in numerous small and medium-sized species known. In the early Miocene, a few species were only left. 1993 42 species of the genus were distinguished. Remains of the widespread genus are known from North America, Europe, Asia and Africa. Some species of the genus were among the most powerful terrestrial carnivores of their time, others fall by their especially small body size, which is roughly equal to that of today's marten on.
In North America the last Hyaenodon disappeared with species such as H. brevirostris in the late Oligocene, in Europe, with species such as H. milloquensis, H. and H. bavaricus leptorhynchus also in the late Oligocene. From the Miocene of Africa three species ( H. andrewsi, H. and H. matthewi pilgrimi ) are also known, which are sometimes placed in a separate genus Isohyaenodon. None of these species reached the dimensions of the Asian species, such as H. gigas and H. weilini. The last Eurasian species seems to have been weilini from the Early Miocene H.. Mainly due to the differences in size, but also due to other morphological features, there are two subgenera: Neohyaenodon with larger species and Protohyaenodon smaller. Currently, we distinguish seven types of Hyaenodon in the late Paleogene of Asia. H. pervagus from the early Oligocene, H. e.sub.minus. From the late Eocene, H. yuanchensis from the Middle Eocene as well as H. mongoliensis, H. incertus, H. gigas and H. chunkhtensis The frühmiozäne type H. weilini is significantly larger than other species of the genus except H. gigas and H. mongoliensis similar style.
Among the larger Hyaenodon ( subgenus Neohyaenodon ) of the late Eocene include the North American species H. horridus, which occurred in the Oligocene, H. montanus and H. megaloides. A smaller type of earliest Oligocene was H. crucians. More precise estimates of Hyaenodon are difficult to determine because the animals had oversized skull compared to today's predators. Thus horridus values obtained for H. that are very far apart at 32 kg and 153 kg, depending on whether one uses the length of the skull or the head -body length as a comparison basis for the calculations. Recent studies show that adult H. horridus may have weighed about 40 kg and not exceeding 60 kg. H. crucians from the early Oligocene of North America is estimated to be about 10 to 25 kg. The two late - Eocene species H. microdon and H. mustelinus were smaller and weighed only about 5 kg. Such particular small forms include the Eurasian species H. filholi and H. Rossignoli from the late Eocene to Oligocene of Europe and H. chunkhtensis from the Oligocene of Asia.