section_path: Evolution/Taxonomy
section_name: Taxonomy
paragraph_text: Taxonomy
  
  Cattle were originally identified as three separate species: Bos taurus, the European or "taurine" cattle (including similar types from Africa and Asia); Bos indicus, the Indicine or "zebu"; and the extinct Bos primigenius, the aurochs. The aurochs is ancestral to both zebu and taurine cattle. They were later reclassified as one species, Bos taurus, with the aurochs (B. t. primigenius), zebu (B. t. indicus), and taurine (B. t. taurus) cattle as subspecies. However, this taxonomy is contentious, and authorities such as the American Society of Mammalogists treat these taxa as separate species.
  
  Complicating the matter is the ability of cattle to interbreed with other closely related species. Hybrid individuals and even breeds exist, not only between taurine cattle and zebu (such as the sanga cattle (Bos taurus africanus x Bos indicus), but also between one or both of these and some other members of the genus Bos – yaks (the dzo or yattle), banteng, and gaur. Hybrids such as the beefalo breed can even occur between taurine cattle and either species of bison, leading some authors to consider them part of the genus Bos, as well. The hybrid origin of some types may not be obvious – for example, genetic testing of the Dwarf Lulu breed, the only taurine-type cattle in Nepal, found them to be a mix of taurine cattle, zebu, and yak.
  
  The aurochs originally ranged throughout Europe, North Africa, and much of Asia. In historical times, its range became restricted to Europe, and the last known individual died in Mazovia, Poland, around 1627. Breeders have attempted to recreate a similar appearance to the aurochs by crossing traditional types of domesticated cattle, producing the Heck breed.
  
  A group of taurine-type cattle exist in Africa; they either represent an independent domestication event or were the result of crossing taurines domesticated elsewhere with local aurochs, but they are genetically distinct; some authors name them as a separate subspecies, Bos taurus africanus. The only pure African taurine breeds remaining are the N'Dama, Kuri and some varieties of the West African Shorthorn.
  
  Feral cattle are those that have been allowed to go wild. Populations exist in many parts of the world, sometimes on small islands. Some, such as Amsterdam Island cattle, Chillingham cattle, and Aleutian wild cattle have become sufficiently distinct to be described as breeds.