Hyaenodon

Hyaenodon; Temporal range: Middle Eocene to Early Miocene (Bartonian to Burdigalian)
	Mounted H. sp. skeleton, Science Museum of Minnesota
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Hyaenodonta
Superfamily:	†Hyaenodontoidea
Family:	†Hyaenodontidae
Subfamily:	†Hyaenodontinae
Tribe:	†Hyaenodontini; Leidy, 1869
Genus:	†Hyaenodon; Laizer & Parieu, 1838
Type species
	†Hyaenodon leptorhynchus; Laizer and Parieu, 1838
Species
	[see classification]
Synonyms
	synonyms of genus: Gobipterodon (Lavrov, 1999) ; Macrohyaenodon (Lavrov & Emry, 1998) ; Macropterodon (Lavrov, 1999) ; Megalopterodon (Dashzeveg, 1964) ; Microhyaenodon (Lavrov, 1999) ; Neohyaenodon (Thorpe, 1922) ; Prohyaenodon (Lavrov, 1999) ; Protohyaenodon (Stock, 1933) ; Pseudopterodon (Schlosser, 1887) ; Taxotherium (Blainville, 1841) ; synonyms of species: H. brachyrhynchus: Canis brachyrhynchus (Blainville, 1841) ; Hyaenodon brachyrhenchus (Lavrov, 1999) ; Hyaenodon cuvieri (Pictet, 1853) ; Hyaenodon leptorhynchus (Dujardin, 1840) ; Hyaenodon parisiensis (Laurillard, 1845) ; Hyaenodon vulpinum (Filhol, 1877) ; Hyaenodon vulpinus (Gervais, 1873) ; Nasua parisiensis (Blainville, 1841) ; Pterodon brachyrhynchus (Pomel, 1846) ; Pterodon cuvieri (Pomel, 1846) ; Taxotherium parisiense (Blainville, 1841) ; ; H. brevirostrus: Hyaenodon brevirostris (Joeckel, 1997) ; Protohyaenodon brevirostrus (Mellett, 1977) ; ; H. chunkhtensis: Microhyaenodon chunkhtensis (Lavrov, 1999) ; ; H. crucians: Hyaenodon leptocephalus (Scott, 1888) ; Hyaenodon minutus (Douglass, 1902) ; Hyaenodon paucidens (Osborn & Wortman, 1894) ; Protohyaenodon crucians (Mellett, 1977) ; Prtohyaenodon crucians (Lavrov, 1999) ; Pseudopterodon minutus (Douglass, 1902) ; ; H. dubius: Hyaenodon aymardi (Filhol, 1882) ; ; H. exiguus: Hyaenodon exigus (Lavrov, 1999) ; Pterodon exiguum (Gervais, 1873) ; ; H. filholi: Hyaenodon compressus (Filhol, 1876) ; Hyaenodon vulpinus (Filhol, 1876) ; Microhyaenodon filholi (Lavrov, 1999) ; Pseudopterodon ganodus (Schlosser, 1887) ; ; H. gervaisi: Hyaenodon ambiguous ; Hyaenodon ambiguus (Martin, 1906) ; ; H. gigas: Macropterodon zelenovi (Lavrov, 1999) ; Neohyaenodon gigas (Lavrov, 1999) ; ; H. heberti: Hyaenodon arnaudi (Depéret, 1917) ; ; H. horridus: Hyaenodon cruentus (Leidy, 1853) ; Neohyaenodon horridus (Thorpe, 1922) ; Neohyaenodon semseyi (Kretzoi, 1941) ; ; H. incertus: Gobipterodon exploratus (Lavrov, 1999) ; Hyaenodon exploratus (Polly, 1993) ; Neohyaenodon incertus (Lavrov, 1999) ; Pterodon exploratus (Dashzeveg, 1985) ; ; H. leptorhynchus: Canis leptorhynchus (Blainville, 1841) ; Hyaenodon bavaricus (Dehm, 1935) ; Hyaenodon cayluxi (Filhol, 1876) ; Hyaenodon martini (Depéret, 1917) ; Hyaenodon milloquensis (Martin, 1906) ; Pterodon leptorhynchus (Pomel, 1846) ; ; H. macrocephalus: Neohyaenodon macrocephalus (Lavrov, 1999) ; ; H. megaloides: Neohyaenodon megaloides (Mellett, 1977) ; ; H. microdon: Microhyaenodon microdon (Lavrov, 1999) ; Protohyaenodon microdon (Mellett, 1977) ; ; H. milvinus: Neohyaenodon milvinus (Lavrov, 1999) ; ; H. minor: Hyaenodon aimi (Cooper, 1926) ; Hyaenodon hantonensis (Lydekker, 1884) ; ; H. mongoliensis: Epipterodon mongoliensis (Lavrov, 1999) ; Megalopterodon mongoliensis (Dashzeveg, 1964) ; Neohyaenodon mongoliensis (Morlo & Nagel, 2006) ; Pterodon mongoliensis (Van Valen, 1967) ; ; H. montanus: Protohyaenodon montanus ; Neohyaenodon montanus (Mellett, 1977) ; ; H. mustelinus: Hyaenodon mustilinius ; Prohyaenodon mustelinus (Lavrov, 1999) ; Protohyaenodon mustelinus (Scott, 1894) ; ; H. pervagus: Hyaenodon neimongoliensis (Huang & Zhu, 2002) ; ; H. pumilus: Microhyaenodon pumilus (Lavrov, 1999) ; ; H. raineyi: Microhyaenodon raineyi (Lavrov, 1999) ; Protohyaenodon raineyi (Gustafson, 1986) ; ; H. requieni: Hyaenodon heberti euzetensis (Depéret, 1917) ; Pterodon requieni (Gervais, 1846) ; ; H. venturae: Hyaenodon exiguus (Stock, 1933) ; Microhyaenodon venturae (Lavrov, 1999) ; Protohyaenodon exiguus (Stock, 1933) ; Protohyaenodon venturae (Mellett, 1977) ; ; H. vetus: Neohyaenodon vetus (Mellett, 1977) ; Pterodon californicus (Stock, 1933) ; ; H. yuanchuensis: Hyaenodon yuanchüensis (Young, 1937) ; ;

Hyaenodon ("hyena-tooth") is an extinct genus of carnivorous placental mammals from the tribe Hyaenodontini, part of the subfamily Hyaenodontinae (which is within the family Hyaenodontidae), that belonged to the now extinct order Hyaenodonta. The genus was found lived in Eurasia and North America from the Middle Eocene to the Early Miocene, from 38 to 17 million years ago, existing for 21 million years. Hyaenodon first evolved in Asia, probably evolving from Propterodon.

The genus currently consists of at least 40 species, although due to sexual dimorphism and intraspecific variation, there were likely fewer species within the genus. The species within the genus ranged in size from H. filholi, which weighed 2 kg (4.4 lb), to H. gigas and H. mongoliensis, which were estimated to be similar in size to Hyainailouros. The largest species were likely the apex predators of their time, with fossil records suggesting they could have occasionally hunted smaller predators. Several species within the genus were cursorial predators, either being ambushing or pounce-pursuit predators. The canines of the animal mediolaterally compressed much like canids, landing shallow bites on their prey. Unlike canids such as wolves, they are thought to have been solitary predators.

The genus saw a decline during the Late Eocene to Early Oligocene, with only one species, H. weilini, being present in the Miocene. Initially, experts hypothesize their decline and extinction was the result of competition with carnivorans. However, over the recent years, this hypothesis has been questioned. Instead, experts now hypothesize the cause of their decline and eventual extinction was the inability to adapt to open environments.