AUSTRALOPITHECINES — ROBINSON 



483 



12 3 



LJ__I_I , „ 



cms '^■^^ 



Figure 2. — Side views of skulls of Australopithecus (top) and Paranthropus (bottom). 



ation exists in the dentition ; the postcanine teeth are massive, being 

 distinctly more robust than those of Australopithecus^ but the canines 

 and incisors are distinctly smaller than in the latter form. There is 

 consequently a sharp change in proportion between the anterior and 

 the postcanine teeth — a unique feature in hominoids. 



Paranthropus thus has a veiy robust skull with strong development 

 of bone and a curiously spheroidal braincase with strong development 

 of rugosities and crests, a wide, dished face, and a dentition specialized 

 quite differently from that of Australopithecv.s. These descriptions 

 are based on female skulls in both cases, but sexual dimorphism does 

 appear to be well developed. Paranthropus was a heavily built, mus- 

 cular animal which probably stood over 5 feet in height and weighed 

 a few hundred pounds. Australopithecus clearly was very small and 

 slenderly built; females apparently were no more than about 4 feet 

 in height and weighed some 40 to 50 pounds. 



Besides these differences, which are obvious enough, there are other 

 important dental differences. The first deciduous lower molar in 



