Persian onager the Asiatic wild ass is known simply as onager, it now also serves as the Persian wild ass's scientific name, as well ("Equus hemionus onager"). Information on the basic biology of the subspecies and how it differs from others is lacking, which hampers conservation efforts. Onagers used to be numerous from the Middle East to China. However, until the 19th century, their population has been reduced from several thousand to a few thousand. Currently, more than 600 Persian onagers are living in the wild. Persian wild asses are known to inhabit mountain steppes, semidesert, or desert plains. They are usually
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