; 



\ 



4^ \\^ 



MAN'S RELATIVES: THE PRIMATES 483 



any living ape; (9) the jaws and facial region are much reduced (Fig. 

 30.6), instead of forming a prominent muzzle; (10) man has a chin; (11) 

 the anterior root of the tongue is attached to a bony prominence in the 

 angle of the jaw, instead of in a "simian pit"; (12) the canine teeth 

 project slightly if at all above the level of the other teeth, and the upper 

 and lower canines do not' interlock nor are there gaps in the tooth arch 

 for reception of the canines of the opposing jaw; (13) the tooth arch is 

 short, broad, and parabolically curved, instead of being long and 

 U-shaped; (14) the molars are subquadrate and typically four-cusped, 

 instead of somewhat elongate and five-cusped; and (15) the body is 

 relatively hairless and completely devoid of long tactile hairs. This is 

 not an exhaustive list; most of the characters mentioned are ones that 

 can be seen or inferred in fossils and 



hence can be used to estimate r^-' V^ C*«* X 



degrees of similarity to man and *%.->— ___i/ 



to ape. 



Tertiary ancestors. As we have 

 mentioned, the oldest known catar- 

 rhine monkey, Parapithecus (Fig. 

 29. 14 A), was found in the lower 

 Oligocene of Egypt. The stock which 

 led to man and apes was already in Fl «- 29 - 14 - T he lower J aws of ioa f Plates 



r ^ and man. A, the most primitive known 



existence at that time, for a small monkey, Parapithecus from the lower Oli- 



gibbonlike animal, Propliopithecus f ocene of Egypt B - * he most primitive 



° . known anthropoid ape, rrophopithecus, also 



(Fig. 29.14B), was found in the same from the lower Oligocene of Egypt. C, the 



deposits. Though very primitive, Miocene anthropoid Dryopithecus (sub- 



f . genus Sivapithecus). ihe human branch 



this animal was either on or not far of the anthropoid stock probably came from 



removed from the direct line Of ^me spocies of this genus. A modern man. 



(Redrawn from Howells, Mankind bo bar, 

 human ancestry. If PropliopitheCUS by permission Doubleday & Company, Inc.) 



was an ancestor of man, he must also 



have been an ancestor of the higher apes. From such a form it is inferred 

 that true gibbons early appeared and went off on their own evolutionary 

 course, which has nothing to do with that of man ; a fossil gibbon is known 

 from the Pliocene of Germany. 



Fossils of arboreal primates are exceedingly rare, but in the Miocene 

 the ape stock began to develop larger size and to adopt more terrestrial 

 habits, and the fossil record becomes a little better. Until recently the 

 Miocene apes were known only from numerous fossil teeth and jaws found 

 in India, Egypt, and several European localities. Teeth are fortunately 

 among the most characteristic parts of mammals and yield considerable 

 information about their possessors. One of the Miocene fossils, Paleosimia 

 from India, seems clearly ancestral to the orangutan. Most of the other 

 fragmentary Miocene fossils are placed in the genus Dryopithecus (Fig. 



