Babirusa actually pierce the flesh in the snout. All species of babirusa are listed as threatened by the International Union for Conservation of Nature (IUCN), shown on their Red List since at least 2010 and current in 2017. The genus is monotypic within the subfamily Babyrousinae, or alternatively considered to form a tribe, Babyrousini, of the subfamily Suinae. To date, only one fossil skull has been found to suggest a larger ancestor. All members of the genus were considered part of a single species until recently, the babirusa or pig-deer, "B. babyrussa", but following the split into several species, this scientific
Wild horse taxonomists considered domesticated and wild horse two subspecies of the same species, the valid scientific name was "Equus caballus" Linnaeus 1758, with the subspecies labeled "E. c. caballus" (domesticated horse), "E. c. ferus" Boddaert, 1785 (tarpan) and "E. c. przewalskii" Poliakov, 1881 (Przewalski's horse). However, in 2003, the International Commission on Zoological Nomenclature decided that the scientific names of the wild species have priority over the scientific names of domesticated species, therefore mandating the use of "Equus ferus" for the horse, independent of the position of the domesticated horse. Przewalski's horse occupied the eastern Eurasian Steppes, perhaps from the Urals