1. "Miohippus " ushered in a major new period of diversification in Equidae . 2. The horse family Equidae and the genus " Equus " evolved in North America. 3. For information on non-horse breeds and species, see Equidae or : Category : Equidae 4. For information on non-horse breeds and species, see Equidae or : Category : Equidae 5. The oldest known fossils assigned to Equidae date from the early Eocene, 54 million years ago. 6. Donkeys can interbreed with other members of the family Equidae , and are commonly interbred with horses. 7. The evolution of Rhinocerotidae and Equidae in the Miocene grasslands proceeded along parallel lines from similar causes. 8. :Actually Equidae is a family, though Equus does appear to be its only surviving genus. 9. :( ec ) The article odd-toed ungulates claims that Equidae has only one surviving genus. 10. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.