Monkeys are haplorhine ("dry-nosed") primates, a paraphyletic group generally possessing tails and consisting of approximately 260 known living species. Many monkey species are
tree-dwelling (arboreal), although there are species that live primarily on the ground, such as baboons. Most species are also active during the
day (diurnal). Monkeys are generally considered to be intelligent, particularly Old
World monkeys.