Whose Bone is it Anyway? Differentiating Pig, Dog, and Human Bone using Histological Methods with Archaeological Applications

Abstract

In prehistoric Polynesia, there are three terrestrial mammals that are found in many faunal assemblages: pig (Sus scrofa), dog (Canis familiaris), and human (Homo sapiens). Fragmented remains of these are often termed as ‘medium mammal’, with no further identification being possible. However, the identification of species in fragmented material has many advantages for zooarchaeologists. Bone histomorphometrics has been demonstrated as a successful methodology for the identification of species in fragmented remains. However, a large number of these studies focus on the differentiation of human from non-human material, and fail to test the level of variation that is produced through intraspecific confounders. These include the age, breed and sex of the individual within a species. This research aimed to determine if the three species could be differentiated beyond human/non-human. It considered the impact of age, sex, breed, and taphonomic preservation on intra-species variation. Histological analyses were used to identify archaeological material including qualitative observations and quantitative measurements of bone microstructure. These assessments included measurements of secondary osteon area and diameter, and Haversian canal area and diameter. Stepwise discriminant function analysis was applied to these results and used to formulate discriminating equations to assist in assigning unknown archaeological fragments to taxon. This study found that age, sex, and breed do create intra-species variability; however, pigs, dogs, and humans could still be differentiated significantly with high success. It also confirmed that archaeological samples could be differentiated with high accuracy even when the samples had a lower degree of histological preservation. These results support the hypothesis that bone histology can be used to identify unknown ‘medium mammal’ fragments in faunal assemblages despite intraspecific variation. Key Words: Bone histology; Pacific; Archaeology; Discriminant Function Analysis; Sus scrofa; Canis familiaris; Homo sapiens; Intra-species variability