Aurochs, or Urus, an extinct ox that is believed to be the ancestor of domestic cattle. The name aurochs is sometimes also applied to the European bison, or wisent. (For a discussion of the wisent, The aurochs once roamed the temperate areas of the Old World in large numbers. They were exterminated by hunters and by destruction of their forest habitat. The last aurochs died in Poland in 1627. The bulls were very large, up to 7 feet (2 m) tall at the shoulder, and had long, curving horns. They were usually black with a white stripe down the back and a white area between the horns. The cows are believed to have been mostly brownish red.

The aurochs was Bos primigenius of the family Bovidae.Their scientific name is Bos taurus.