Wild or domestic? A 3D approach applied to crania to revisit the identification of mummified canids from ancient Egypt

Many of the millions of animals dedicated to the deities in Ancient Egypt were canids. In contrast to the rare textual sources, the abundance of skeletal remains offers the opportunity to address the question of whether wild or domestic canids were mummified. However, species identification from osteological material remains problematic because it relies on a simple qualitative appreciation or traditional biometric analyses with low discriminatory power, often paired with incomplete comparative reference samples. Here we propose a new method of identification based on cranial form using a 3D landmark-based geometric morphometric approach (GMM). We built predictive methods using a large reference sample of numerical models of crania of modern canids, including a variety of domestic breeds (N = 69, 38 different breeds) as well as feral dogs (N = 31), and all species of wild canids present in Africa or the Near East and likely to have been present in Ancient Egypt (N = 157). We then applied these methods to a sample of ancient canid remains (N = 41). We compared the effectiveness of multivariate discriminant analyses based on 3D GMM to that using traditional linear morphometric measurements (LMM) commonly taken in the field by archaeozoologists. GMM performs better than LMM in determining the domestic/wild status with cross-validation percentages reaching over 97.5%, and in determining the species among a reduced sample of wild canids with a 96.4% rate (versus 88.2% and 85.2% in LMM respectively). With 3D GMM, we detected the presence of dogs, but also African golden wolves and, for the first time, Near Eastern grey wolves among the mummies.