Articles relating to the Bos, a genus of wild and domestic cattle. Bos is often divided into four subgenera: Bos, Bibos, Novibos, and Poephagus, but including these last three divisions within the genus Bos without including Bison is believed to be paraphyletic by many workers on the classification of the genus since the 1980s. The genus as traditionally defined has five extant species, but this rises to eight when the domesticated varieties are counted as separate species, and ten when the closely related Bison is also included.