Revised taphonomic perspective on African Plio-Pleistocene fauna.

A recent article in PNAS by Sahle et al. (1) entitled “Hominid butchers and biting crocodiles in the African Plio–Pleistocene” is an important contribution to our theoretical and methodological approaches to human origins research. It emphasizes the problem of equifinality in prehistoric studies (different agencies producing the same or similar results or end products), cutmarks from stone tools and toothmarks from crocodiles on fossil bones in this case. The pioneering taphonomic work of Brain (2, 3) in South Africa was a brilliant combination of experimental work, such as feeding carcasses and bones to carnivores (hyaena and leopard) and rodents (porcupine); actualistic studies examining animal bone remains of Hottentot settlements (modified by humans and their dogs); and examination of fossil bone assemblages from paleoanthropological fossil sites (Swartkrans, Sterkfontein, Makapan, and Kromdraai). This has set a methodological standard for paleoanthropologists to strive for and refine. In the mid-1980s, TimWhite and I undertook a world survey of bone surface modification of hominid fossils from Africa, Europe, and Asia to evaluate evidence of possible hominid aggression and/or cannibalism. We encountered a myriad of marks on hominid bones that appeared to include those produced by carnivore toothmarks, stone tool cutmarks, rodent gnaw-marks; “random striae” (marks with little patterning that suggested modification from trampling/sediment abrasion); and postfossilization modification of bone from excavation, preparation, and the use of measuring tools (e.g., metal calipers and craniometers). This was well before any major appreciation of the potential role that crocodile predation and feeding could have on bones. We did suggest, however, a possible equifinality between toothmarks produced by mammalian carnivores and those that could be produced by teeth of hominids themselves (4).