 Przewalski's horse has long been considered the only 'true' wild horse extant in the world today, never having been domesticated.However, a 2018 DNA study suggested that modern Przewalski's horses may descend from the domesticated horses of the Botai culture.Przewalski's horse was described in 1881 by L. S. Poliakov, although the taxonomic position of Przewalski's horse remains controversial and no consensus exists whether it is a full species ("Equus przewalskii"), a subspecies of the wild horse ("Equus ferus przewalskii", along with the other subspecies, domesticated horse "E. f. caballus", and the extinct tarpan "E. f. ferus"), or even a subpopulation of the domestic horse.