THE EVOLUTION OF MAN 



741 



Figure 36.4. Old ^Vorld monkeys (Nilgiri langur). (Courtesy of the American 

 Museum of Natural History.) 



In the same Oligocene deposits in which Parapithecus was found 

 occur fossils of the first anthropoid ape, Propliopithecus. This small, 

 gibbon-like animal probably descended from Parapithecus and is widely 

 believed to be close to the common ancestor of all the anthropoid apes 

 and man. In the evolution of the apes there has been a trend toward a 

 general increase in body size and an increase in the brain and skull. Most 

 apes move by swinging from one branch to the next, and have developed 

 long arms and fingers. The hind legs are rather short. 



Apes were widely distributed throughout Europe, Asia and Africa 

 during the middle and later Cenozoic. Fossils of Limnopithecus, believed 

 to be ancestral to the gibbons, and Proconsul, on the line of evolution of 

 the other apes, have been found in lower Miocene deposits in Africa. 

 Paleositnia, apparently the ancestor of the orang-utan, is known from 

 Miocene deposits in India. The genus Dryopithecus includes anthropoid 

 apes that flourished in Europe and Asia during the Miocene and Pli- 

 ocene; they were probably the ancestors of modern gorillas, chimpan- 

 zees and man. 



321. The Modern Great Apes 



The family Pongidae includes the four living great apes, the gibbon, 

 orang-utan, chimpanzee and gorilla. The gibbon is smaller than man 

 but the other three are as large as or larger than we are. They all have 

 extremely rudimentary tails, arms that are longer than their legs, op- 

 posable thumbs and great toes, a semierect posture, and chests which 

 are broad and flat like man's rather than thin and deep like the 



monkey's. „ j i. 



The gibbon, found in Malaya, is the smallest and perhaps most 

 primitive of tlie great apes. It has extraordinarily long arms, which reach 



