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, East Asia including Japan, and onto North America. While all bison species are classified in their own genus, they are sometimes bred with domestic cattle (genus Bos) and produce fertile offspring called beefalo or zubron.