Holozoa

A bovid (family Bovidae) is any of almost 140 species of cloven-hoofed ruminant mammal at least the males of which bear characteristic unbranching horns covered in a permanent sheath of keratin.

The family is widespread, being native to Asia, Africa, Europe and North America, and diverse: members include bison, African buffalo, water buffalo, antelopes, gazelles, sheep, goats, muskoxen, and domestic cattle.

The largest bovid, the gaur, weighs well over a ton and stands 2.2 metres high at the shoulder; the smallest, the royal antelope, weighs about 3 kg and stands no taller than a large domestic cat. Some are thick-set and muscular; others are lightly built, with small frames and long legs. Many species congregate into large groups with complex social structures, but others are mostly solitary. Within their extensive range, they occupy a wide variety of habitat types, from desert to tundra and from thick tropical forest to high mountains.

Most members of the family are herbivorous, except most duikers, which are omnivorous. Like other ruminants, bovids have a four-chambered stomach which allows them to digest plant material, such as grass, that cannot be used by many other animals. Such plant material includes much cellulose, and no higher animal can digest this directly. However, ruminants (and some others like kangaroos, rabbits and termites) are able to use microorganisms living in their gut to break down cellulose by fermentation.