FwJj70 – A potential Early Stone Age single carcass butchery locality preserved in a fragmentary surface assemblage

Abstract

The Okote Member (1.39–1.53 million-years-ago) of the Koobi Fora Formation preserves a rich and well-resolved lithic archaeological record, but comparatively little is known about the paleoecology of stone tool use during hominins' carnivorous foraging behavior. Archaeological butchery traces are typically found in fragmentary assemblages with well-preserved cortical surfaces that include multiple butchered individuals and carcass parts, but conclusions about butchery behavior, including skeletal element profiles and element and individual estimates may be impacted by specimen identifiability and differential preservation during palimpsest assemblage formation. Here we present an analysis of a fragmentary surface assemblage of fossil bone, designated FwJj70, that includes butchered and tooth-marked specimens and fragments of additional mammal carcasses to explore the archaeological visibility of carcass consumption at the lower boundaries of data quality – in particular, imprecise specimen identifiability and poor assemblage preservation. FwJj70 includes a similar composition of mammalian families and size classes in comparison with the fauna recorded along 400 m of the same stratigraphic horizon but possesses less weathered specimens with fewer post-fossilization and dry fractures, suggesting that bone specimens were rapidly buried. Excavation in search of an in situ origin of the surface assemblage recovered three specimens, but did not reveal a clear archaeological horizon. FwJj70 includes 40 identifiable specimens from at least 21 elements and six mammalian individuals. Eight specimens from a minimum of four elements and a single individual preserve evidence of hominin butchery and may come from a single size-three mammal carcass. However, poor specimen identifiability and ex situ context lead to a coarse estimate of the true number of butchered animals in the assemblage, blurring the distinction between a single carcass butchery episode and consumption of multiple animals, and masking the activity of carnivores. Despite this equifinality, the anatomical location of butchery marks at FwJj70 provides evidence of discrete aspects of hominins' tool-assisted carnivorous foraging niche, including early access to limb flesh packages, bone marrow consumption, and competition with other carnivorous consumers.