Kromdraai cranium. Despite the fact that the vault is represented by little 

 more than the squamous portion of the left temporal bone, the greater 

 wing of the left sphenoid, the lower part of the left parietal, and part of 

 the left side of the occipital bone, Schepers made a number of attempts at 

 reconstruction. These studies yielded values ranging from 575 to 680 c.c, 

 "650 c.c. representing the average" (Schepers 1946, p. 238). The figure 650 

 was cited by Broom and Robinson in 1948, by Schepers in 1950, and by 

 Dart in 1956. However, as Le Gros Clark pointed out, 



The remains of the skull found at Kromdraai do not permit of even an approxi- 

 mate estimation of cranial capacity, but it is at least apparent from the size of the 

 endocranial casts of the preserved temporal and cerebellar regions of the cranial 

 wall that it must have exceeded that of the Sterkfontein specimens. [Le Gros 

 Clark 1964, p. 133] 



All of the aforementioned specimens from Swartkrans and Kromdraai 

 were so imperfect that not one of the estimates cited, ranging from 650 to 

 "probably over 1000," has gained general acceptance, and none of them 

 has been included in my tabulations (Tobias 1963, 1967a, 1968b). 



The first convincing evidence that robust australopithecines might 

 have had cranial capacities of the same order of magnitude as the gracile 

 ones was provided by the hyper-robust specimen, Olduvai hominid (Old. 

 Horn.) 5 from Olduvai, found by Dr. Mary Leakey in July 1959. The 

 specimen is discussed in the ensuing section. Its capacity was no larger than 

 that of some of the larger-brained of the A. africanus sample (530 c.c, 

 Tobias 1963). 



This specimen brought a clear demonstration that, if the estimates of 

 capacity of the larger-brained skulls of A. africanus were accurate, then the 

 cheek-teeth, jaws, and bony buttresses of the masticatory apparatus in the 

 robust australopithecines were disproportionately large, without any ac- 

 companying enlargement of the brain (Tobias 1967a, p. 80). A year after 

 the discovery of the Olduvai specimen Robinson, in an address to the South 

 African Association for the Advancement of Science in July i960, revised 

 his estimate of the cranial capacity of the robust australopithecines, lower- 

 ing the high values quoted above to a modest 450 to 550 c.c— the same 

 order of size as obtains in the gracile A. africanus (Robinson 1961). He said 

 then of the australopithecines in general, "The endocranial volume appears 

 to be only about 500 cm. 3 — I know of no sound evidence at present indicat- 

 ing a brain significantly larger than this. The range is evidently about 



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