632 APES xxiv. 3- 



mainly terrestrial, walking on all fours and sleeping either on the 

 ground (males) or at a small height (females and young). Like the 

 other apes they show much local variation but all may be referred to 

 a single species, G. gorilla. G. gorilla beringei is a mountain form that is 

 more fully terrestrial than the others (Fig. 410). 



The similarities and differences between these animals and man 

 will be discussed later. Their relationship with the other catarrhines is 

 clearer. The lower jaw of *Parapitheais of the Egyptian lower Oligo- 

 cene contained teeth of a pattern that could have given rise to those of 

 the Pongidae as well as the Cercopithecidae (Fig. 397). In the same 

 beds was found another jaw, which is definitely that of an ape, 

 *Propliopithecus. Here the molars have a distinctly five-cusped pattern, 

 with protoconid and metaconid in front and a large heel, carrying a 

 hypoconid laterally and entoconid medially, and also a posterior 

 hypoconulid. Some such animal could have given rise to *Limnopi- 

 thecus of the Miocene and *Pliopithecus of the Pliocene, animals 

 similar to the gibbons and living in the woods of Europe and Africa. 

 Great apes were found quite widely in the Old World during the 

 Miocene and Pliocene. The earliest of these, *Proconsul from the 

 lower Miocene of Kenya, showed a combination of characters of 

 cercopithecids, great apes, and man. The skull was more lightly built 

 than in apes, with no brow ridges. The tooth rows converged anteriorly 

 as in *Parapithecns. The incisors were small and like those of man but 

 the canines were large and the first lower premolar was sectorial as in 

 apes. The limb bones suggest that the gait was terrestrial and quad- 

 rupedal, and that the brachiating habit had not yet evolved. 



*Dryopithecus from the middle and upper Miocene of Africa, 

 Europe, and India was closer to the apes, with U-shaped dental 

 arcades. On the other hand, *Ramapithecus from the Miocene and 

 Pliocene of India showed human characteristics in the rounded upper 

 arcade of the teeth, small canines, and other features. 



Several other types are known and evidently the apes were wide- 

 spread, varied, and successful animals in the Miocene and there are 

 among them plenty of signs of the characteristics both of the modern 

 apes and men. The remains of *Oreopithecus from the Pliocene of 

 Italy show a curious mixture of characters. It was not a brachiator, 

 but its method of locomotion is not clear. The lower molars have four 

 cusps arranged in pairs as in monkeys but not united by ridges. The 

 upper molars resemble those of apes but the small canines, absence 

 of diastema, and bicuspid first lower premolar have led some to place 

 it close to man. 



