Article Outline Physical characteristics. Human beings and the other primates. Scientists classify about 230 species of mammals as primates.
Some scientists classify tree shrews among primates as prosimians.
Some kinds of primates Physical characteristics. Primates have a number of characteristic physical features, but not every primate has each of these features. The anthropoids have more of the characteristic primate features than do the prosimians. In general, the anthropoids are also larger. They have relatively large and complex brains and are more intelligent than the prosimians.