Osteodontokeratic Industry - History

History

In 1947, Wilfred Eitzman (a local schoolteacher), visited the Makapansgat Limeworks in Limpopo, South Africa, where he collected a number of fossil remains, including those of extinct baboon species, which originated from the Australopith-bearing, Member 3 Grey breccia layers. Eitzman promptly sent some of this fossil material to Prof. Raymond Dart at the University of the Witwatersrand in Johannesburg for thorough inspection. Dart examined 58 baboon skulls from Eitzman's collections, and recognized a repeated pattern of depressed fractures on the cranial vaults of a number these specimens. Consistent with this pattern, he also found that 4 out of the 6 known Australopith skulls from the Member 3 layers showed similar cranial fractures, although Dart struggled to find an adequate explanation that would account for the frequency of this damage. Eventually Dart concluded that this pattern could have only resulted from “purposeful violence…inflicted by implements held in the hands,” suggesting that southern African Australopiths used long bones (e.g. femurs and humeri), mandibles, horn cores, etc. as hunting weaponry to satisfy their hyper-carnivorous diets (1949). Thus, the ODK hypothesis implied that the rise of the Australopithecus genus from 'hominoid' to 'hominin,' meaning from an ‘ape-adaptive grade’ to a more ‘human-adaptive grade,’ was borne from the ability of early hominin species to use tools, more specifically weapons.

Dart published numerous journal articles on the subject of the ODK hypothesis, which received considerable backlash from his contemporaries. In 1957, he released a comprehensive volume entitled, “The Osteodontokeratic Culture of Australopithecus prometheus” which outlined his arguments for the validity of the ‘predatory transition from Ape to Man’ (see Dart 1953). To justify his arguments, Dart relied on critical lines of evidence that substantiated the validity of ODK culture, although his critics would eventually turn his evidence against him to refute the hypothesis altogether (see below). Dart suggested that the breakage patterns of the so-called bone implements from the Member 3 Grey breccia layers from Makapansgat displayed evidence of being purposefully broken by the early Australopiths, through cracking and twisting, while fresh. Dart's opinion was that this damage was in no way characteristic of predatory or scavenging animals (e.g. hyenas), and so must have been the result of early hominin dietary activities, mostly likely to access marrow. Furthermore, after the analysis of over 7,000 faunal remains from the Member 3 Grey breccia material, Dart found a statistical over-representation of certain skeletal elements, such as distal humeri, metapodial bones and mandibles. He concluded that such skewed representational patterns could have only resulted from the selection and transportation of fleshy carcass parts of animals into the Makapansgat cave system by Australopiths. Lastly, Dart assigned specific tool uses to different bones elements, e.g. a 'mace' for antelope humeri, etc., similar to the manner in which Mary Leakey created tool types to account for various core morphologies in the Oldowan assemblages at Olduvai Gorge.