Order Primates
摘要
The order Primates includes all monkeys; it is one of the mammal groups that do not have unique characteristics to help differentiate them from the rest of the mammals, but it has a combination of traits that allows its differentiation. Among those that stand out are fore and hind feet with five digits or plantigrades; thumbs with nails, generally opposable (at least in the fore feet); presence of a clavicle; vision stereoscopic and in color; brain hemispheres well developed; flattened nails. Their distribution is tropical with a few exceptions. One order, Haplorhini, with two families, Atelidae and Cercopithecidae (introduced), ranges in North America.