Mouflon scientific literature as separate species, "Ovis musimon" and "Ovis orientalis". The mouflons are also sometimes treated as a subspecies of the domestic sheep, "Ovis aries", named with the same subspecific epithet as above: "O. a. musimon", "O. a. ophion", etc. Based on comparison of mitochondrial cytochrome b gene sequences, three groups of sheep ("Ovis") have been identified: Pachyceriforms of Siberia (snow sheep) and North America (bighorn and Dall sheep), Argaliforms (argali) of Central Asia, and Moufloniforms (urial, mouflon, and domestic sheep) of Eurasia. However, a comparison of the mitochondrial DNA control region (CR) found that two subspecies of urial, "Ovis
Wild horse cranial and metacarpal differences, indicates the presence of only two subspecies in postglacial times, the tarpan and Przewalski's horse. At present, the domesticated and wild horses are considered a single species, with the valid scientific name for the horse species being "Equus ferus." The wild tarpan subspecies is "E. f. ferus", Przewalski's horse is "E. f. przewalskii", and the domesticated horse is "E. f. caballus". The rules for the scientific naming of animal species are determined in the International Code of Zoological Nomenclature, which stipulates that the oldest available valid scientific name is used to name the species. Previously, when