Osteodontokeratic Industry - Initial Criticisms & Dart's Rebuttal

Initial Criticisms & Dart's Rebuttal

Immediately after the initial publication of Dart’s ODK hypothesis in 1949, a number of his colleagues refuted the idea as an example of interpretation beyond the limits of scientific evidence. Dr. Wilfrid Le Gros Clark (1957) criticized Dart’s “over-emphatic” writing style, and suggested that his hypothesis relied mainly on the fact that no other feasible hypothesis could make sense of the evidence Dart had complied, rather than on the meticulousness of the scientific methods that Dart used to corroborate the existence of the ODK culture.

More notably, Dr. Sherwood Washburn had conducted field research in the Wankie Game Reserve in Southern Rhodesia (now Zimbabwe), where he observed lion kills that were subsequently scavenged by smaller carnivores (e.g. hyenas, jackals and wild dogs). Washburn noted that the process of prey dis-articulation, and in some cases transport, by carnivores was a highly selective process, which produced similar skeletal part representation patterns to those that Dart found in the Member 3 bone assemblages from Makapansgat (cf. Maguire et al. 1980). He published the now well-known article “Australopithecus: The Hunters or the Hunted?” (1957) based upon this research, in which Washburn suggested that southern African Australopiths did not actually hunt other animal species, but rather were hunted and accumulated by cave-dwelling carnivores, most likely by hyenas. This was supported by the presence of two extinct hyenid species found in the Member 3 Grey breccia material, Pachycrocuta brevirostris and Hyaena makapani, as well as the abundance of hyena coprolites within these layers (which had been well-known at the time). Thus, Washburn refuted Dart’s ODK hypothesis based upon the same lines of evidence used to support it, and suggested that various hyena species were more likely responsible for the accumulation of bone material in the Australopith-bearing layers at Makapansgat.

Despite such refutations, Dart defended the ODK hypothesis for some time relying upon fieldwork conducted by some of his colleagues that seemed to dismiss the claims of Washburn and others, most notably the hyena bone-collector hypothesis. For example, Alun Hughes (1954), then Dart's assistant, undertook research in the Kruger National Park, South Africa to investigate the bone accumulation habits of hyenid species, reporting that hyenas did not seem to amass bone material inside their dens, and instead consumed prey directly after the kill or in open-air scavenging sites with little evidence of transport behavior (see Dart 1965). Thus, Dart rebutted Washburn's criticisms in arguing that the early Australopiths must have been responsible for the bone accumulations at Makapansgat due to the abundant amount of faunal material found within the cave system, as well as the nature of the breakage patterns. Coupled with the discovery of stone tool assemblages thought to be associated with the robust Australopith species (Zinjanthropus boisei, now classified under the genus Paranthropus) from Olduvai Gorge by Mary and Louis Leakey, this amounting evidence seemed to sway the argument in Dart’s favor. Furthermore, Dr. John T. Robinson (1959) (a colleague of Dr. Robert Broom at the Transvaal Museum, and a co-founder of the famous adult Au. africanus skull Sts 5, known as Mrs. Ples), had found a bone tool at Sterkfontein he believed to be used by Au. africanus, which also seemed to corroborate the ODK hypothesis.

However, Dart’s refutation of the bone-collecting habits of hyenas was short-lived as an overwhelming body of research has found that hyenas do, in fact, accumulate bone material inside caves used as dens. Before Hughes’s work in the Kruger National Park, modern zoological research focusing upon hyenas had never been correlated with palaeontological or palaeoanthropological studies of this nature. Due to the inception and on-going significance of taphonomic and palaeozoological research within these fields, it is now well-known and widely accepted that hyenid species transport and accumulate bone material within cave systems used as dens, which can ultimately result in fossil assemblages (see Maguire et al. 1980 and Kuhn et al. 2010).