The primates are a group of mammals that includes some of the most intelligent animals. The major kinds of primates are humans, apes, monkeys, tarsiers, lemurs, and lorises. There are more than 300 species, or types, of primate. These different types have many physical features in common.For this reason scientists believe that they may share a common ancestor.he major kinds of primates are humans, apes, monkeys, tarsiers, lemurs, and lorises. There are more than 300 species, or types, of primate. These different types have many physical features in common. For this reason scientists believe that they may share a common ancestor.