if he has not made allowances for the childhood status of the Taung skull, 

 this omission would lower the mean by only about 7 ex. 



The robust australopithecines 



Swartkrans and Kromdraai. Although a large number of hominid 

 crania has been recovered from Swartkrans, not one of them is sufficiently 

 complete and undistorted to have permitted an accurate estimate to be 

 made of the endocranial capacity. True, statements about the capacity of 

 the Swartkrans (SK) specimens are not wanting in the literature. 



Broom and Robinson (1952) recorded estimates for 2 child crania from 

 Swartkrans; the first was 700 c.c. (for an adolescent, supposed female) and 

 the other 750 to 800 c.c. (for a six- to seven-year-old, presumed male). For 

 3 adult crania from Swartkrans the same authors had provided estimates of 

 about 750 (SK 48), probably over 800 (SK 46), and probably over 1000 c.c, 

 respectively. Robinson stated that a juvenile from Swartkrans had a brain- 

 case length 20 to 25 mm. greater than that of the Taung child and a 

 breadth proportionately greater. He claimed, in consequence, "From this 

 and the adult crania in our possession it seems that the general order of 

 brain size of the adult P. crassidens * is comparable with that of the smaller 

 specimens of Pithecanthropus— roughly 800 cm. 3 " (Robinson 1952, p. 197). 

 All of the foregoing estimates were based on crushed, damaged, and in- 

 complete specimens, not one of which allowed a precise estimate to be 

 made. Consequently, few or no workers have accepted these claims for the 

 capacity of the Swartkrans specimens. Nevertheless, weakly based as these 

 guesses were, it had become accepted by a number of workers that the 

 cranial capacity of A. robustus (= Paranthropus) was greater than that of 

 the gracile A. ajricanus. This is implied, for instance, by Le Gros Clark in 

 his discussion on cranial capacity. He states: 



The Swartkrans skulls and jaws are considerably larger than those found at 

 Sterkfontein, but, unfortunately, none of the calvariae are sufficiently well pre- 

 served to permit accurate estimates of cranial capacity. [Le Gros Clark 1964, 



P- 133] 



The impression that the robust australopithecine had a larger cranial 

 capacity than the gracile was supported by the estimate for the original 



most provisional of Holloway's reestimates, that for MLD 37/38, and use the previously accepted 

 value of 480 c.c, together with Holloway's new figures for the other 5 crania, this still gives a 

 sample mean of 450 c.c, an estimate of the standard deviation, derived from the sample range, 

 of 22.49 cc > an d a coefficient of variation of 5.00 per cent. 

 * His name, at that time, for the robust australopithecine from Swartkrans. 



21 K 



