Creodonta

Creodonta Temporal range: 63.3–8.8 Ma PreꞒ Ꞓ O S D C P T J K Pg N Early Paleocene to Late Miocene
Various creodonts of the Eocene of Colorado, United States. From top: Tritemnodon, Patriofelis, Machaeroides, and Sinopa
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Mirorder:	Ferae
Order:	†Creodonta Cope, 1875[1]
Families
†Hyaenodontidae †Oxyaenidae
Synonyms
list of synonyms: Creodontia Creodontidae (Winkler, 1893)[2] Creodontiformes (Kinman, 1994)[3] Creodontina (Pearse, 1936)[4] Creophaga (Kretzoi, 1945)[5] Hyaenodontia (Romer, 1966)[6] Paracarnivora (Kretzoi, 1929)[7] Pseudocreodi (Matthew, 1909)[8] Subdidelphia (Trouessart, 1879)[9]

Creodonta ("meat teeth") is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the Oxyaenids and the Hyenodonts, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa.^[10]

Creodonts were the dominant carnivorous mammals from 55 to 35 million years ago, peaking in diversity and prevalence during the Eocene.^[11] The first large, obviously carnivorous mammals appeared with the radiation of the oxyaenids in the late Paleocene.^[12] During the Paleogene, "creodont" species were the most abundant terrestrial carnivores in the Old World.^[13] In Oligocene Africa, hyaenodonts were the dominant group of large flesh-eaters, persisting until the middle of the Miocene.

"Creodont" groups had an extensive range, both geographically and temporally. They are known from the late Paleocene through the late Oligocene in North America, the early Eocene through late Oligocene in Europe, from the late Paleocene through late Miocene in Asia, and from the late Paleocene to the late Miocene in Africa.^[14] While most were small-to-medium sized mammals, among their number was Sarkastodon, one of the largest mammalian land predators of all time, weighing an estimated 800 kg.^[15]

Though often assumed to have been outcompeted by carnivorans, there is little empirical support for this. The last genus, Dissopsalis, became extinct about 11.1 million years ago.

Most modern paleontologists agree both "creodont" families are related to Carnivora, but are not their direct ancestors. It is still unclear how closely the two families are related to each other. In general, classification is complicated by the fact that relationships among fossil mammals are usually decided by similarities in the teeth, but the teeth of hypercarnivorous species may evolve similar shapes through convergent evolution, to deal with the mechanics of eating meat.^[16]

"Creodonts" share with the Carnivora, and many other predatory mammal clades, the carnassial shear, a scissors-like modification of upper and lower cheek teeth that was used to slice muscle tissue. This adaptation is also seen in other clades of predatory mammals.