The Analysis of Cutmarks on Archaeofauna: A Review and Critique of Quantification Procedures, and a New Image-Analysis GIS Approach

Abstract

Zooarchaeologists utilize a diverse set of approaches for quantifying cutmark frequencies. The least quantitative method for cutmark analysis relies on composite diagrams of cutmarks overlain on drawings of skeletal elements (diagramatic methods). To date, interpretations of these data have generally relied on qualitative and subjective assessments of cutmark frequency and placement. Many analysts count the number of fragments that have a cutmark, regardless of the number of cutmarks on the fragments (fragment-count data). Others count the number of cutmarks (cutmark-count data). Both can be expressed as simple counts (NISP data), or as a count of some more-derived measure of skeletal element abundance (MNE data). All of these approaches provide different types of data and are not intercomparable. Several researchers have shown that fragmentation of specimens impacts the frequency of cuts, and we show here that fragmentation impacts all these current approaches in ways that compromise comparative analysis when fragmentation differs between assemblages. We argue that cutmark frequencies from assemblages with differing levels of fragmentation are most effectively made comparable by correcting the frequency of cutmarks by the observed surface area. We present a new method that allows this surface area correction by using the image analysis abilities of GIS. This approach overcomes the fragmentation problem. We illustrate the power of this technique by comparing a highly fragmented archaeological assemblage to an unfragmented experimental collection.