A paper just out in Nature by McPherron et al suggests that a set of marks found on two bones recovered from the surface very near a locality for which an estimated date can be obtained were caused in antiquity by stone tools wielded by hominids. The date predates any prior known chipped stone tool artifacts of the kind that would leave such marks. The absence of chipped stone tools in the archaeological record in which a claim of a cut marked bone seems unlikely, but it may not be. Earlier research done by Brooks and your truly, and reported mainly as conference papers (e.g. here) and summarized in Panger et all 2002, suggests that prior to drying conditions beginning between 2.5 and 3.0 million years ago the stone tool record would be highly diffuse and almost impossible to find archaeologically.
On the other and, stone tool marks, according to some of key taphonomists and archaeologists are almost always ambiguous, or at least difficult to identify positively (see Tappen and Harris 1995 and Dominguez-Rodrigo et al 2005). A stone tool is a rock. It can scratch a bone. There are other rocks. They can scratch bones too. Telling the difference between a rock scratching a bone and a rock scratching a bone is inherently difficult. One way to do this is to look at a zillion cut marks with stone tools and characterize them metrically and qualitatively (done) and look at a bunch of trample marks where bones are ground and stomped into stony or pebbly ground and characterize those marks (done, but not as much because it is less fun) and see if you can get none overlapping sets of characteristics.
You don’t get non-overlapping characteristics, but you do get different looking patterns. So, you can then look at unknown marks and see what pattern they fit. One aspect of the pattern, by the way, is where on the bone the mark is; Some anatomical locations make more sense than others for butchery. On the other hand, one of the reasons we want to look at marks on bones is to find out how the animals were butchered. The tautology meter tends to go off about now.
I’ve seen a lot of cutmarks. I’ve even been the silent coauthor on a couple of papers in which cutmarks were the main focus. (Such is the job of a faculty spouse, I suppose.) And, yes, you saw it coming, I’ve supervised a hand full of undergraduate honors theses, masters theses, and PhD theses where this was a strong element. And, I helped build a lab designed to look at these suckers.
And when I look at the pictures of the marks on the bones shown in this paper, I see stone tool cutmarks.
But given that stone tool cutmarks are marks made by rocks on bones …. we just can’t be sure. But it is cool nonetheless.
The authors of the paper conclude:
The bones presented here are the earliest evidence for meat and marrow consumption in the hominin lineage, pre-dating the known evidence by over 800 kyr. Pending new discoveries, the only hominin species present in the Lower Awash Valley at 3.39 Myr ago to which we can associate this tool use is A. afarensis5,15. Whether A. afarensis also produced stone tools remains to be demonstrated, but the DIK-55 finds may fit with the view that stone tool production pre-dates the earliest known archaeological sites and was initially of low
intensity (one-to-a-few flakes removed per nodule) and distributed in extremely low density scatters across the landscape such that its archaeological visibility is quite low16. The evidence presented here offers a first insight into an early phase of stone tool use in hominin
evolution that will improve our understanding of how this type of behaviour originated and developed into later, well recognized, stone tool production technologies.
We will need more to be certain of this dramatic assertion, but part of the process is publishing the observations that we have. We would also like to see some of the cutmarked bones found in situ in an excavation. Perhaps in time…
Citation for the paper:
McPherron, S., Alemseged, Z., Marean, C., Wynn, J., Reed, D., Geraads, D., Bobe, R., & Béarat, H. (2010). Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia Nature, 466 (7308), 857-860 DOI: 10.1038/nature09248
Other sources cited:
Brooks, A. and G. Laden. 1994. The Effects of the Landscape on the Archaeological Record of Foragers: Contrasting the Kalahari and the Ituri Rain Forest. Paper presented at the Society of Africanist Archaeologists, Bloomington.
Dominquez-Rodrigo, Travis Pickering, Sileshi Semaw, and Michael Rodgers. 2004. Cutmarked bones from Pliocene archaeological sites at Gona, Afar, Ethiopia: implications for the function of the world’s oldest stone tools. Journal of Human Evolution, 48:2(109-121).
Panger, M. A., Brooks, A. S., Richmond, B. G. & Wood, B. 2002. Older than the Oldowan? Rethinking the emergence of hominin tool use. Evol. Anthropol. 11,(235-245)
Tappen, M. and J.W.K. Harris. 1995. Comment on possible cut marks and taphonomic history of Senga 5A in the Western Rift Valley, Zaire. Journal of Human Evolution. 29:5(483-486).