Ontogenetic scaling and lithic systematics: method and application

Stone tools tend to be classified according to a mix of functional, morphological, and technological attributes. This practice results in confusions when large-scale assemblage comparisons are made with the aim of investigating phylogenetic relationships, as functional and cultural information is aggregated. It is argued here that functional criteria must be assessed separately, and that resharpening, as a uniform, repeated, conscious behavioral process of tool maintenance that indexes use and function, can provide a solution to this problem. The subject of this article is a quantitative method for extracting and comparing resharpening trajectories. The method is an adaptation of ontogenetic scaling methods from biology, and is based on obtaining a mathematical representation of shape and size, and finding a relationship between the two. Elliptical Fourier analysis is applied to stone tool contours in order to extract shape information, and then a series of regressions of shape on size provide trajectory vectors. The angles between these are then calculated and subjected to a variety of multivariate statistical tests. A case study involving several European Middle Paleolithic bifacial and unifacial tool assemblages is presented. The results show that resharpening and maintenance can be independent of morphology and technology, suggesting that there are strong grounds for focusing on functional systematics separately.