A reanalysis of strontium isotopes from a skull and mandible cemetery at the Crenshaw site: Implications for Caddo interregional warfare

The 352 individuals from a skull and mandible cemetery at the Crenshaw site (3MI6) in southwest Arkansas have been argued to represent non-Caddo victims of warfare from other regions. Strontium isotopes taken from 80 individuals were processed as part of a NAGPRA grant and have been used to claim they supported evidence of interregional warfare between the Caddo and groups in the Southern Plains. A second analysis suggested that the strontium isotopes were subject to diagenesis and unusable for interpretations. A reanalysis of the results and comparison with recent literature shows that the strontium isotope results are valid. This article demonstrates the importance of considering context during analysis. The deer and people from different times and contexts have different strontium isotope ratios. Going beyond evaluating if they are local or non-local, this difference shows the potential for strontium isotope ratios to document settlement pattern change through time. Computing the biologically available strontium range using the mid-range of comparative samples (instead of the mean) is offered as a more theoretically appropriate method for investigating populations suspected of coming from the hinterlands or surrounding sites, such as those at Crenshaw. When the mid-range method is used, all individuals match the local range. Strontium isotopic data from other regions including the Midwest and Southern Plains suggest that the skulls and mandibles were not likely coming from these regions. Instead, it is hypothesized that they represent a local burial practice associated with a dispersed settlement pattern at the time the Caddo were adopting maize as a staple.