PLoS ONE (Jan 2015)
Diachronic Change within the Still Bay at Blombos Cave, South Africa.
Abstract
Characteristically shaped bifacial points are stone artefacts with which the Middle Stone Age Still Bay techno-complex in Southern Africa is identified. Traditional approaches such as chaîne opératoire and two-dimensional metrics in combination with attribute analyses have been used to analyse variability within Still Bay point assemblages. Here we develop a protocol to extract and analyse high resolution 3-dimensional geometric morphometric information about Still Bay point morphology. We also investigate ways in which the independent variables of time, raw-material and tool size may be driving patterns of shape variation in the Blombos Cave point assemblage. We demonstrate that at a single, stratified Still Bay site points undergo significant modal changes in tool morphology and standardization. Our results caution against (1) treatment of the Still Bay as a static technological entity and (2) drawing demographic inferences stemming from grouping Still Bay point collections within the same cultural label.