Preferential Processing of High Return Rate Marrow Bones by Oldowan Hominids: a Comment on Lupo

Experimentally-determined caloric return rates for adult female wildebeest long bones (Lupo, 1998) are positively and significantly correlated with medium mammal (size class 3 and 4) MAU at FLK Zinjanthropus, Olduvai Gorge, Tanzania. We infer that hominids at this locality were preferentially extracting marrow from long bones with high post-procurement return rates. Including the experimentally-determined return rates from head contents and mandible marrow (Lupo, 1998) maintains a strong positive correlation. Our results differ from Lupo's (1998) because she also included return rates for the first phalanx in her correlation. We argue that, unlike the return rates for long bones, first phalanx return rates as determined by Lupo do not include all relevant processing times and hence overestimate the actual return rate.