Donkey have worked together with humans for millennia. Traditionally, the scientific name for the donkey is "Equus asinus asinus" based on the principle of priority used for scientific names of animals. However, the International Commission on Zoological Nomenclature ruled in 2003 that if the domestic species and the wild species are considered subspecies of one another, the scientific name of the wild species has priority, even when that subspecies was described after the domestic subspecies. This means that the proper scientific name for the donkey is "Equus africanus asinus" when it is considered a subspecies, and "Equus asinus" when it is
Equus scotti assigned fossils from the Anza-Borrego Desert in California, tentatively interpreted to represent "E. bautistensis", to "E. scotti". One of the reported locations farthest south in the Americas is Pali Aike National Park in Chile. Equus scotti Equus scotti (translated from Latin as Scott's horse, named after vertebrate paleontologist William Berryman Scott) is an extinct species of "Equus", the genus that includes the horse. "E. scotti" was native to North America and likely evolved from earlier, more zebra-like North American equids early in the Pleistocene Epoch. The species may have crossed from North America to Eurasia over the Bering land bridge