Reconstruction
Bouri lies in the Middle Awash of Ethiopia, ninety kilometres south of Gona, and its 2.5-million-year-old deposits produced something rarer than stone tools: the bones those tools were used on. Fossilised animal remains from the site carry cut marks made by stone edges, together with percussion damage where limb bones were deliberately broken. What Bouri lacks is the artefacts themselves. No associated stone tools were recovered, so the butchery here is recorded entirely in its consequences. That absence turns out to be useful rather than a shortcoming, because the two Ethiopian sites answer complementary halves of one question. Archaeology of this period is full of stone tools whose purpose has to be inferred from their shape, and full of broken bones whose breakage could be explained by carnivores, trampling or sediment pressure. At Gona, tools occur with fractured faunal remains but the bone surfaces are less well preserved. At Bouri, the bone surfaces are well preserved and carry unambiguous tool marks but no tools survive. Read together the evidence converges: the earliest stone technology was used for processing animal carcasses, for meat and for bone marrow, and this is demonstrated rather than assumed. The two mark types matter separately. Cut marks show flesh being removed from bone, which means access to muscle tissue that teeth alone could not strip cleanly from a large animal. Percussion damage shows limb shafts being smashed, which means access to marrow. Marrow is the more interesting of the two. It is dense in fat, it is sealed inside bone where no other scavenger can reach it, and on an African savannah where lean meat is abundant seasonally but fat is chronically scarce, it is arguably the higher-value prize. A hominin able to break bones is not competing with hyaenas and cats for the same flesh; it is exploiting a resource they leave behind. There is a limit worth stating. Cut marks establish that something with a stone edge processed these carcasses. They do not establish who, since no hominin fossil is associated with the marked bones, and they do not establish how the animals died. Hunting and scavenging leave the same signature once a carcass is on the ground, and the debate over which dominated at this date is not resolved by marks alone. What Bouri fixes is a date and a behaviour: by 2.5 million years ago, hominins in the Awash were systematically dismembering large animals with stone and breaking their bones for what was inside.
Historical context
Roughly 2.5 million years ago, the earliest members of the genus Homo were appearing in eastern Africa alongside Australopithecus and Paranthropus. Fire was unused. The Middle Awash held river channels, lake margins and open grassland, with hippopotamus, elephant, three-toed horses and abundant antelope, hunted by sabre-toothed cats and hyaenas whose kills hominins may have scavenged. Global climate was cooling and drying, and African grasslands were expanding at the expense of woodland. No hominin had left the continent.
Evidence
Zooarchaeological
StrongAnimal bones carry stone-tool cut marks and percussion damage on well-preserved surfaces, directly evidencing flesh removal and deliberate bone breakage.
Dating
StrongArgon dating and stratigraphy constrain the deposits to approximately 2.5 million years.
Food identification
ModerateMeat and marrow are evidenced by the two distinct mark types. Prey taxa are identified from the bones, but which animals hominins specifically processed is less securely established than the fact of processing.
Preparation method
ModerateCutting and percussion are inferred from mark morphology. No tools were recovered at the site, so the implements themselves are known only from the marks they left.
Archaeological attribution
LimitedNo hominin fossil is associated with the marked bones, and the marks cannot distinguish hunting from scavenging, since both produce the same signature once a carcass is on the ground.
Sources
- 1.Jean de Heinzelin, J. Desmond Clark, Tim White, et al. (1999). Environment and Behavior of 2.5-Million-Year-Old Bouri Hominids. Science 284(5414), 625-629. doi:10.1126/science.284.5414.625Scientific literature
- 2.Sileshi Semaw, Michael Rogers, Jay Quade, et al. (2003). 2.6-Million-year-old stone tools and associated bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia. Journal of Human Evolution 45(2), 169-177. doi:10.1016/s0047-2484(03)00093-9Scientific literature
Limitations
- moderatearchaeological attribution
No stone tools were recovered at Bouri and no hominin fossil is associated with the marked bones. The butchery is inferred entirely from marks on the bones, and the implements and their users are both unidentified.
- moderatehistorical interpretation
Cut marks cannot distinguish hunting from scavenging, since both leave identical traces once a carcass is on the ground. Any framing of these hominins as hunters goes beyond what the evidence supports.
