In This Issue

Traces and pits found on the surfaces of fossilized bones have been used to infer the use of stone tools by hominids for butchering carcasses. But whether the marks represent stone tool butchery or trampling and biting by carnivores remains unsettled, calling into question the inferred ages of hominid stone tool use. Yonatan Sahle et al. (pp. 13164–13169) analyzed mammal bones from the Plio–Pleistocene fossil record in Ethiopia’s Middle Awash site that were dated to around 4.2 million years ago, 3.4 million years ago, and 2.5 million years ago. Combined with contextual evidence, analysis of cuts, marks, grooves, and pits on dozens of fossil bones, which included a pair of Australopithecus humeral shafts and an equid femur recovered from water-deposited sands, suggests that several of the marks were likely the result of crocodile bites rather than stone tool use. Further, analysis of a bovid tibial midshaft specimen and a bovid mandible proved inconclusive, leaving open the possibility of one or both agents. Given that previous interpretations of hominid subsistence and tool use were based on the analysis of relatively small fossil assemblages from such sites as Tanzania’s Olduvai Gorge and Ethiopia’s Hadar village, where the Australopithecine fossil Lucy was discovered, the findings suggest the need for reassessment of assemblages used to infer early hominid behavior, according to the authors. — P.N.