Cut Mark Cluster Geometry and Equifinality in Replicated Early Stone Age Butchery

Abstract

Early Stone Age cut marks created during tool-assisted carnivory potentially offer inferences into hominin butchery behaviour and access to complete or defleshed carcasses. Actualistic butchery trials of 16 goat and cow halfcarcasses were completed by an experienced butcher with replicated Oldowan tools to investigate how the geometric organisation of cut mark clusters reflects flake versus core tool use and bulk muscle versus scrap defleshing. A cluster of cut marks is defined as a series of adjacent cut mark striations that occur at an anatomical location and are bounded by unmarked cortical surface. Tool type and butchery action were predicted to differentially mark certain long bone portions and influence cluster attributes. Moulds of 613 cut mark clusters were photographed and measured using ImageJ software (National Institutes of Health, Bethesda, Maryland, USA) for cluster area, cut mark count, median cut mark length and standard deviation of cut mark length and angle. Analysis suggests the following results: (i) cluster attributes are correlated;(ii) changes in cluster geometry are related to increasing cut mark count and length but not tool type or defleshed muscle amount; (iii) large clusters occur on large animals; and (iv) long bone midshaft portions are cut-marked during both bulk and scrap muscle defleshing. Analysis of 179 cut mark clusters on long bone shafts of sizes 1-4 mammals from three Okote member assemblages at Koobi Fora, Kenya, shows that archaeological clusters have a similar number of marks when compared with experimental clusters but are significantly smaller, have shorter median marks and include less deviation in mark length and angle. Archaeological clusters corroborate that increasing area is positively correlated with cut mark count, median mark length and standard deviation of mark length and angle. A quantitative inferential model that links cut mark cluster geometry to tool type or the amount of muscle defleshed is not supported by these data.

Experimental butchery study investigating the influence of timing of access and butcher expertise on cut mark variables

“…Although many of our predictions were supported by the data collected from the butchery experiment, we did not find statistically significant correlations among any of the variables we investigated. The lack of correlation between prebutchery flesh quantity and cut mark number or length concurs with studies that have found the meat quantity on a carcass to be unrelated to cut mark number (Lupo & O'Connell, ; Merritt, ; Pobiner & Braun, ), but contrasts with assertions that variability in cut mark number would be strongly indicative of either a lesser (Binford, , ) or greater (Bunn & Kroll, ) prebutchery flesh quantity. Our data also do not support predictions or data collected on previous observations of modern butchery that more experienced butchers would leave fewer butchery marks (Domínguez‐Rodrigo, ; Haynes & Krasinski, ; Lyman, ; Padilla, ).…”

“…The length of cut marks has received little theoretical or experimental focus (but see Merritt, and Soulier & Morin, ). Although cut mark length was not statistically correlated with the amount of prebutchery flesh quantity or butcher expertise in this study, cut marks on the partially defleshed limbs were on average shorter than those in the fully fleshed limbs (7.24 and 9.06 mm, respectively).…”

“…Yet Egeland, Welch, and Nicholson's () butchery experiments found that cut mark angle did not differ significantly between carcass parts butchered by a single versus multiple novice butchers. In his modern butchery experiments, Merritt () found that experimentally produced cut marks were generally longer and had a larger standard deviation than cut marks from an Early Stone Age site in Koobi Fora, Kenya. In sum, there is currently a lack of clear relationship in patterning of many measurable archaeological cut mark variables (such as number, location, angle, and length) and behavioural or ecological contexts of butchery we would like to be able infer from these variables.…”

Cut marks on bone surfaces: influences on variation in the form of traces of ancient behaviour

“…The attrition of tool edges during butchery is something that has previously been highlighted [16,23,24]. Here we show that this attrition is related to the opening angle of a cut mark.…”

“…Initial discussions about the use of marks on bone surfaces as a means to interpret behaviour in the past warned about the necessity to understand the mechanism through which traces of behaviour are recorded on the surfaces of bones [12]. This is critical to understand how hominin diet changed through time because the morphology of cut marks may be able to provide information about the timing of access to carcasses [16]. While palaeoanthropologists have come a long way in answering this call to relate static traces of the past to the dynamic processes that created them we remain largely unaware of the mechanical factors that affect the morphology of bone surface modifications [17].…”