The set of marks on this fossil bone recovered from DIK-55 will likely be discussed for quite some time to come. Cut marks on fossil bone are part of the study of taphonomy. First defined in the 1940s, taphonomy is the study of the processes that occur between death and burial of an organism, and that includes the manner of death, and the decomposition and decay of tissues. (see S.K. Donovan's book The Processes of Fossilization for more information).
Paleontologists have been peering at cut marks on fossil bones since the 1820s, although the science didn't take off until the 1970s. The debates about cut marks intensified when scanning electron microscopy was first used to examine cut marks in detail.
Experimental archaeology replicating cut marks (essentially, people butchering animals with stone tools and comparing the marks to fossil ones) has been part of the process of understanding these taphonomic leftovers, but there is still some debate over the interpretations. Do these marks represent the use of stone tools to bash and cut meat off bones of animals?
No doubt about it, if Alemseged and colleagues are correct, and these indeed are cut marks representing the butchering of (theoretically) scavenged animal carcasses, then we need to rethink both the meaning and timing of the Lower Paleolithic, and the skills that were available to which of our early hominid ancestors.
But are these Cutmarks?
Butchery experiments in an attempt to reproduce these types of marks were conducted and reported by Dominguez-Rodrigo and colleagues in 2012. They found that the cut marks produced by the experiments were quite dissimilar to these deep linear cuts, and are of the opinion that the Dikika marks are the result of the movement of fossils on or within their deposit. Thus, say Dominguez-Rodrigo and colleagues, the marks do not represent evidence of butchering by Dikika Australopithecines.
As a baseline, the study used previous experimental research using stone tools and bone to differentiate between cutmarks made during butchering versus what scholars called "trampling", the effects of incidental animal movement stepping on fresh bone and grinding against the ground. Comparing high resolution photographs of the bones from Dikika, the scholars came to the conclusion that the Dikika 'cutmarks' were created by contact of fresh bone with humanly unmodified rocks (called HUR), or other taphonomic incidents.
Sources and Further Information
- Selam (the "Dikika Baby", A. afarensis discovered by Alemseleged et al.)
- Timeline of the Lower Paleolithic
- Australopithecus
- Experimental archaeology
Domínguez-Rodrigo M, Pickering TR, and Bunn HT. 2012. Experimental study of cut marks made with rocks unmodified by human flaking and its bearing on claims of ~3.4-million-year-old butchery evidence from Dikika, Ethiopia. Journal of Archaeological Science 39(2):205-214.
McPherron SP, Alemseged Z, Marean CW, Wynn JG, Reed D, Geraads D, Bobe R, and Bearat HA. 2010. Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia. Nature 466:857-860.
