Pickering, T.R., Domínguez-Rodrigo, M., Heaton, J.L., Yravedra, J., Barba, R., Bunn, H.T., Musiba, C., Baquedano, E., Diez-Martín, F., Mabulla, A., Brain, C.K., 2012. Journal of Archaeological Science.This paper compares ungulate ribs from Oluvai dated ~1.2mya with those butchered and eaten by modern hunter-gatherers as well as with carnivore assemblages. They suggest that further to tooth- and cut-marks found on the Olduvai bones the ‘peeling back’ of the rib outer surface is another hallmark of hominin activity also seen in modern human rib processing (and in chimp, but only very rarely in carnivore, rib eating). They argue that carnivores target the organs contained in the rib cage so the fact that hominins seem to have had primary access to ribs suggests that they were actively hunting and defending prey from other carnivores or driving away carnivores from fresh kills. Interestingly, as Tamas pointed out, the authors do not mention charred bones, meaning there is no evidence of cooking in this assemblage.