Equidae

Equidae (commonly known as the horse family) is the taxonomicfamily of horses and related animals, including asses, zebras, and many extinct species known only from fossils. The family evolved more than 50 million years ago, in the Eocene epoch, from a small, multi-toed ungulate into larger, single-toed animals. All extant species are in the genusEquus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families. It is more specifically grouped within the superfamilyEquoidea, the only other family being the extinct Palaeotheriidae.

The term equid refers to any member of this family, including any equine.