Cheek teeth are bunodont in some forms, but more commonly selenodont . The premolars tend to be relatively small and not fully molariform. Most artiodactyls have modified stomachs , the extreme case being that of groups such as antelope and deer, which have distinctive, four-chambered stomachs. This arrangement appears to be an adaptation that allows members of these groups to make use of microorganisms to decompose cellulose into digestible components. Cellulose is an important constituent of plant tissue that most mammals cannot digest.
Artiodactyls are native to all continents except Australia and Antarctica.
The group contains a number of domesticated species. The fossil record of artiodactyls is ancient, going back at least to the earliest Eocene. The dominance of this order is correlated with the decline of perissodactyls. It has been suggested that artiodactyls caused most perissodactyls to disappear, or that the disappearance of perissodactyls permitted the radiation of artiodactyls, but we probably can never know whether either of these relationships occurred. Artiodactyls are usually divided into several suborders.