Monkeys are furry animals with long, fur-covered tails and hands with thumbs. Monkeys are either classified as Old World, meaning those from Africa and Asia, or as New World, meaning those from Central and South America. Both groups differ slightly in physical appearance.
New World monkeys have flatter noses. They are also more specialized for life in the trees. The capuchin monkey is the only species from this group that spends any time at all on the forest floor, and even it is mostly arboreal. Many have grasping tails that help them stay balanced when moving from branch to branch. Their body size runs from small to medium, as lighter bodies have an easier time leaping in the tree tops. Most do not have fingernails.
Old World monkeys are stockier and have skulls with prominent ridges. They are medium to large sized, as many are adapted for life on the ground rather than in the trees. Old World monkeys have tails that are not able to grasp branches, and they posses nails on all their fingers and toes.
Most monkeys of both types have dull-colored fur. However, some have colorful patches of bare skin on their bodies. Mandrills, a type of Old World monkey, have red and blue skin on their cheeks.