xxiii. 1-2 PRIMATE CHARACTERS 603 



Family 2. Cercopithecidae. Old World monkeys. Oligocene- 

 Recent. Africa, Asia 

 *Mesopithecus, Miocene; Macaca, rhesus monkey, macaque, 

 Asia, N. Africa; Papio, baboon, Africa; Mandrillus, 

 mandrill, Africa; Cercopithecus, guenon, Africa; Presbytis, 

 langur, E. Asia; Colobus, guereza, Africa 

 Superfamily 3. Hominoidea 



Family 1. Pongidae. Apes. Oligocene-Recent 



*Propliopithecus, Lower Oligocene, Egypt; *Pliopithecus, 

 Lower Miocene, Europe, Africa; *Dryopithecus, Miocene, 

 Africa, Asia; *Oreopithecus, Pliocene, Europe; * Australo- 

 pithecus, Pleistocene, S. Africa; * Proconsul, Miocene, 

 Africa; Hylobates, gibbon, SE. Asia; Pongo, orang-utan, 

 E. Indies; Pan, chimpanzee, Africa; Gorilla, gorilla, Africa 

 Family 2. Hominidae. Man. Pleistocene-Recent 



* Pithecanthropus (= *Sinanthropus), Java and Pekin man, 

 Pleistocene, E. Asia; Homo, man (all living races). Pleisto- 

 cene-Recent 



2. Characters of primates 



Linnaeus reserved his order Primates for the monkeys, apes, and 

 men, distinguishing them thus from the other mammals, Secundates, 

 and all other animals, Tertiates. The term primate carries with it 

 the implication that the animals in the group are not only the nearest 

 to ourselves but are also in some sense the first or most completely 

 developed members of the animal world. We shall try to examine this 

 belief in accordance with the principles adopted earlier and to inquire 

 whether we and our relatives can be said to be the highest animals in 

 the sense that we possess a system of life able to survive under the 

 most varied and unpromising conditions. 



The earliest eutherians of the Cretaceous were probably arboreal ; 

 the primates have continued this habit and with it they retain many 

 of the features present at the beginning of mammalian history, for 

 instance the five fingers and toes and the clavicle. Primates already 

 existed in the Palaeocene, 65 million years ago and have a longer geo- 

 logical history than any other placentals except the insectivores and car- 

 nivores. It is not surprising, therefore, that it is difficult to separate the 

 primates from the insectivores; the tree shrews, for instance (p. 584), 

 have several times been transferred from the one order to the other. 



The primates have retained many primitive mammalian features, 

 some of which have become strongly accentuated for arboreal life. 



