EVOLUTION OF MAN 237 



Homo sapiens also shared by the australopithecines. The differences 

 largely relate to large jaws and teeth and small brains. While it seems evi- 

 dent that the australopithecines demonstrate for us a stage passed through 

 by man in his evolution, very possibly the actual specimens being discov- 

 ered in South Africa were not members of a population which was literally 

 ancestral to later men. But similar forms, living perhaps in other regions 

 and as yet undiscovered, very likely were the actual ancestors. In this 

 connection we should like to learn more of australopithecines living in re- 

 gions other than South Africa. In 1959 the skull and tibia of an australopi- 

 thecine were found in Tanganyika, thereby extending the known range of 

 the group into East Africa. Called Zinjanthropus boisei by its describer, 

 L. S. B. Leakey (1959), this fossil differs from those of the South African 

 forms in some respects and may approach the structure of modern man 

 more closely than do these latter. Interestingly, the bones came from a 

 Lower Pleistocene campsite and were accompanied by stone tools and the 

 bones of animals used as food. 



More recently Dr. Leakey has discovered remains of two more indi- 

 viduals, a child and an adult, in the same region. Preliminary reports indi- 

 cate that these remains are older, but more manlike, than those of Zinjan- 

 thropus, from which they differ in various ways. Interestingly enough, the 

 canine teeth resemble those of Proconsul. In this fascinating field further 

 discoveries, filling gaps in knowledge and changing ideas, may be expected 

 almost daily. 



Turning to regions outside Africa, we may note that Robinson (1956) 

 considered that a hominid known from fragmentary remains found in Java 

 and customarily called Meganthropus was actually an australopithecine; 

 Le Gros Clark ( 1955 ), on the other hand, considered that it was a Pithe- 

 canthropus. Perhaps this difference of opinion is in itself revealing of the 

 manner in which the australopithecines approached Pithecanthropus in 

 structure. At any rate, our ignorance of the distribution of australopithe- 

 cines outside Africa is as yet almost complete. 



The actual ancestors of later men may have lived at an earlier time than 

 did the known specimens of australopithecines. The latter are considered 

 to date from the early Lower Pleistocene; Robinson ( 1956) stated that they 

 "must also have been living in the Pliocene," but no Pliocene fossils of 

 them are known. The remains of the next succeeding type of man. Pithe- 

 canthropus, are found in deposits considered to be from the beginning of 

 the Middle Pleistocene (Le Gros Clark, 1959). Thus some hundreds of 

 thousands of years may have intervened between the known australopithe- 

 cines and Pithecanthropus. If the actual ancestors were older than the 



