Oligocene canids

Hesperocyon is an extinct genus of canids belonging to the subfamily Hesperocyoninae of the canid family that was endemic to North America, ranging from southern Canada to Colorado. It appeared during the Uintan age, –Bridgerian age (NALMA) of the Mid-Eocene– 42.5 Ma to 31.0 Ma. (AEO). Hesperocyon existed for approximately .

The genus Leptocyon (Greek: leptos slender + cyon dog) includes 11 species and is the oldest known canine. They were small and weighed around . They first appeared in North America around 34 million years ago in the Oligocene, at the same time as the Borophaginae, with whom they share features, indicating that these were two sister groups. Borophaginae skull and dentition were designed for a powerful killing bite compared with the Leptocyon which were designed for snatching small, fast-moving prey. The species L. delicatus is the smallest canid to have existed. At the close of their genus 9 mi

Archaeocyon ("ancient dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch 32-24 Ma., existing for approximately . Species of Archaeocyon are among the earliest known borophagines, although a species of Otarocyon has a slightly earlier first appearance. Fossils have been found across the northern Great Plains and along the west coast of North America.

Cynodesmus ("dog link") is an extinct genus of omnivorous canine which inhabited North America during the Oligocene living from 33.3—-26.3 Ma and existed for approximately .

Phlaocyon (from Greek phlao, "eat greedily" and cyon, "dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lives from the Early Oligocene to the Early Miocene epoch 33.3–16.3 Mya, existing for approximately . It is closely related to Cynarctoides.

Cormocyon is an extinct genus of borophagine canid native to North America. It lived from the Oligocene to the Early Miocene, 30.8—20.6 Mya, existing for about . It is regarded as a primitive, transitional member of the Borophagini tribe.

Sunkahetanka is an extinct monospecific genus of the Hesperocyoninae subfamily of early canids native to North America. It lived during the Oligocene, 30.8—26.3 Ma, existing for approximately . In form, it was intermediate between the small Cynodesmus and the later Enhydrocyon, the first hypercarnivorous, "bone-cracking", canid.

Mesocyon ("middle dog") is an extinct genus of the Hesperocyoninae subfamily of early canids native to North America. It lived from the Oligocene to Early Miocene, 30.3—20.3 Ma, existing for approximately . Fossils are known from Oregon, southern California and the northern Great Plains. It was roughly coyote-sized, and the first known canid to have a primarily meat-based diet.

Otarocyon ("large eared dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch, about 33.3—20.6 Ma (million years ago). Fossils have been found only in Montana, Wyoming, and South Dakota.

Cynarctoides is an extinct genus of the Borophaginae subfamily of canids endemic to North America. It lived from the Early Oligocene to the Middle Miocene, 33.3—13.6 Mya, existing for approximately . Seven species are currently recognised, all of which are estimated to have weighed no more than .

Ectopocynus ("strange dog") is an extinct genus of bone crushing canid which inhabited North America from the Oligocene to the Early Miocene. It lived from 33.3 to 16.0 Ma and existed for approximately .

Caedocyon ("fit for cutting dog") is an extinct monospecific genus of bone crushing canid which inhabited western North America during the Oligocene 30.8—20.6 Ma, existing for approximately .

Rhizocyon ("root dog") is an early member of the subfamily Borophaginae, an extinct subgroup of canids that were endemic to western North America during the Oligocene epoch, living from ~31—24.5 Ma., existing for approximately .

Philotrox is an extinct monospecific genus of the Hesperocyoninae subfamily of early canids native to North America. It lived during the Oligocene, 30.8—26.3 Ma, existing for approximately . In form, it was intermediate between the small Cynodesmus and the later Enhydrocyon, the first hypercarnivorous, "bone-cracking", canid.

Osbornodon ("Osborn's tooth") is an extinct genus of canid that were endemic to North America and which lived from the Oligocene to the Early Miocene, 33.9—15.97 Ma (AEO), existing for approximately . It was the last surviving genus of the hesperocyonine subfamily, the oldest subfamily of canids. The genus is named for Henry Fairfield Osborn. ==Species== Seven known species of Osbornodon existed: Osbornodon brachypus Cope 1881 Osbornodon fricki Wang 1994 (18 Ma) Osbornodon iamonensis Sellards 1916 (21 Ma) Osbornodon renjiei Wang 1994 (33 Ma) Osbornodon sesnoni Macdonald 1967 (32 Ma) Osbornod

Oxetocyon ("beginning dog") is an extinct monospecific genus of the Borophaginae subfamily of canids native to North America. It lived during the Early Oligocene epoch, existing for approximately . Fossils have been found in Nebraska and South Dakota.

Enhydrocyon is an extinct genus of bone crushing canid which inhabited North America during the Oligocene and Early Miocene, 30.8—20.4 Ma, existing for approximately .