Identification of metal residues associated with bit-use on prehistoric horse teeth by scanning electron microscopy with energy dispersive X-ray microanalysis

Our ability to identify evidence of the use of horses for transportation from archaeozoological remains is important for improving our understanding of the role of horses in socioeconomic changes throughout prehistory. When a horse is used with a bit, the bit can come into contact with the anterior ('front') surface of the lower second premolar (P₂). Here, results of X-ray microanalysis, undertaken in a variable pressure scanning electron microscope, of chemical elements on the anterior surface of four archaeological horse P₂ are presented. Analysis of dental materials (enamel and cementum) returned expected results, with calcium, phosphorous and oxygen dominating. Iron-rich residues are also identified on the front of two of the teeth, which are interpreted here as deriving from contact with iron bits. It is proposed that such analyses may provide a useful additional method for identifying bitting damage in archaeological horses or corroborating interpretations made from macroscopic examinations.