''Cynarctus'' is an extinct genus of the

Borophaginae The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America du ...

subfamily of

canid Canidae (; from Latin, ''canis'', "dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found within the ...

s native to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. The genus was first founded by

W. D. Matthew William Diller Matthew Royal Society, FRS (February 19, 1871 – September 24, 1930) was a vertebrate paleontologist who worked primarily on mammal fossils, although he also published a few early papers on mineralogy, petrological geology, one on ...

in 1901, based from a pair of lower jaws, ''Cynarctus saxitilis,'' found in the

Pawnee Creek Beds The Pawnee Creek Beds (also Pawnee Creek Formation) is a geologic formation in Colorado. It preserves fossils dating back to the Neogene period. See also * List of fossiliferous stratigraphic units in Colorado * Paleontology in Colorado The l ...

of Colorado. It lived during the Middle to Late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

16.0—10.3 mya, existing for approximately . Fossils have been uncovered in Colorado, California, Maryland, western Nebraska, and Texas. It was likely an omnivore, and lacked the bone-cracking adaptations found in some later borophagines. Newer findings have proved the genus to be described as a large dog-like raccoon, a result from combining characteristics from Canidae with

Procyonidae Procyonidae is a New World family of the order Carnivora. It comprises the raccoons, ringtails, cacomistles, coatis, kinkajous, olingos, and olinguitos. Procyonids inhabit a wide range of environments and are generally omnivorous. Character ...

Species

Cynarctus crucidens

Found by Mr. A. C. Whitford, from the Department of Geology at The University of Nebraska, and collected for the Nebraska Geological Survey in 1913. This species of Cynarctus is represented by a right lower jaw that was located in beds (Lower Pliocene) in Sioux County, Nebraska. Having an almost complete dentition, it was found to have slight differences in the structure of the mouth/jaw area from the species of C. saxatilis. Findings confirmed that the premolars were more reduced, teeth were narrower, canine smaller, and that the jaw was relatively longer and more slender than species C. saxatilis.

Cynarctus acridens

Collected by Erwin H. Barbour and Harold J. Cook, for the same Nebraska Geological Survey in 1913, as the species C. crucidens was found. This species is also represented by a part of a lower right jaw and is considered to be the smallest that has so far been discovered. It differs from the species C. saxitilis and C. crucidens, whom have a heavy and broad posterior cinguli, by having a comparatively very weak posterior cingulum.

Cynarctus fortidens

A part of a right maxilla (Early Pliocene age) was located 75 feet above stream on the west side of Turkey Creek in Donely County, Texas. The fossil was obtained by W. W. Dalquest, during June 1960. The principal cusps of the teeth are rounded, suggesting that it was mainly frugivorous. This species differs from C. crucidens as it lacks an accessory cusp between the protocone and paracone of the fourth upper premolar.

References

*Wang, X., R.H. Tedford, and B.E. Taylor. 1999
Phylogenetic systematics of the Borophaginae (Carnivora, Canidae)
Bulletin of the American Museum of Natural History, 243:1-391. Borophagines Miocene canids Miocene mammals of North America Prehistoric carnivoran genera Taxa named by William Diller Matthew {{canid-stub