Equus ovodovi

Equus ovodovi is an extinct species of equine known from the late Middle Pleistocene to the mid-late Holocene of North and East Asia.

Description

Equus ovodovi was slightly larger than the Asiatic wild ass, with one individual from Proskurjakov cave having an estimated body mass of around 196.5 kilograms (433 lb). E. ovodovi can be distinguished from wild asses based on its larger and more robust limb bones. The skull differs from that of the European wild ass (Equus hydruntinus), with which they were previously confused, by having a narrower supra-occipital crest, and having less broad choanae. Their teeth also differ from those of European wild ass by having more elongate protocones.

Ecology

Isotopic analysis of specimens from the Holocene of China suggests a preference for C4 plants.

Evolution and extinction

Equus ovodovi has been suggested to be the last surviving member of the subgenus Sussemionus, which first appeared in North America over 2 million years ago, and was formerly present across Afro-Eurasia. Some later studies questioned its relationship to the subgenus Sussemionus.

Genetic evidence suggests that it was more closely related to zebras and asses than to horses. Initial genetic analysis based on the mitochondrial DNA found the exact relationship to be uncertain, but analysis of the full nuclear genome suggests that zebras and asses are more closely related to each other than either are to E. ovodovi, with the ancestor of E. ovodovi estimated to have diverged from the common ancestor of zebras and asses around 2.5 million years ago, though there had been gene flow into the Equus ovodovi lineage from both the last common ancestor of zebras and asses and the last common ancestor of zebras, as well as gene flow from the Equus ovodovi lineage into the last common ancestor of asses.