Onager never been domesticated. They are among the fastest mammals, as they can run as fast as 64 km/h (40 mph) to 70 km/h (43 mph). The onager is closely related to the African wild ass, as they both shared the same ancestor. The kiang, formerly considered a subspecies of "Equus hemionus", diverged from the Asiatic wild ass and has been acknowledged as a distinct species. The onager formerly had a wider range from southwest and central to northern Asian countries, such as Israel, Saudi Arabia, Iraq, Jordan, Syria, Afghanistan, Russia, and Siberia. During early 20th century, the species lost most
Onager ancestor of all modern equids (members of the genus "Equus") lived around 5.6 (3.9–7.8) million years ago (Mya). Direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a more recent 4.07 Mya for the most recent common ancestor within the range of 4.0 to 4.5 Mya. The oldest divergencies are the Asian hemiones (subgenus "E. (Asinus)", including the kulan, onager, and kiang), followed by the African zebras (subgenera "E. (Dolichohippus)", and "E. (Hippotigris)"). All other modern forms including the domesticated horse (and many fossil Pliocene and Pleistocene forms) belong to the subgenus "E. (Equus)" which