Bison or buffalo are large, even-toed ungulates in the genus Bison within the subfamily Bovinae.Two extant and four extinct species are recognized. Of the four extinct species, three were North American: Bison antiquus, B. latifrons, and B. occidentalis. The fourth, B. priscus, ranged across steppe environments from Western Europe, through Central Asia, and onto North America.Of the two surviving species, the American bison, B. bison, found only in North America, is the more numerous.