The utility of histomorphometrics in distinguishing between human and non-human rib bone: osteon area, perimeter, and circularity
This investigation explored the utility of mean osteon area, perimeter, and circularity as parameters for distinguishing between human and non-human bone. Although species of origin can be readily ascribed to undamaged remains, this evaluation can become difficult, if not impossible, when bone macrostructure has been obscured through taphonomic processes such as thermal alteration or extreme fragmentation. If mature Ovis aries, domestic sheep, and human osteon metrics area are significantly different, then osteon metrics can be useful parameters for distinguishing between these tissues and, thus, determining the species of origin for a bone sample of unknown provenience. This investigation consisted of histological analysis of cortical bone from 35 O. aries rib samples. O. aries samples were acquired from Riverslea Farm in Epping, New Hampshire (n = 30) and Cedar Ledge Farm in Somers, Connecticut (n = 5). Mean osteon area, perimeter, and circularity were assessed by manually tracing calibrated digital images of rib cross-sections using the ImageJ software from the National Institute of Health (NIH, Bethesda, MD). The results presented here indicate (1) that there are statistically significant histomorphometric differences between species, specifically goat and sheep, (2) that there are significant histomorphometric differences based on the anatomical, intra-rib sampling location, and (3) that the osteon metrics discussed here are may be poor parameters by which to ascribe the species of origin for remains with no known provenience, based on comparisons with findings from other publications.