Standardization of Postcranial Nonmetric Traits and Their Utility in Ancestry Analysis

Abstract

Throughout the forensic anthropology and archaeology disciplines, postcranial nonmetric traits have varied in name, descriptions, and scoring methodology. This research focuses on synthesizing the literature to select the most prevalent traits, standardize their definitions, and create corresponding line drawings for each trait. By defining and illustrating each trait and its different states, a novel visual approach for scoring a suite of 11 postcranial nonmetric traits was created. Data collection allowed for the calculation of frequency distributions for ancestry comparison. Results indicate that four traits have statistically significant differences between two groups, American Blacks and American Whites, when using the Bonferroni adjusted p-value of 0.0045. These traits include spinous process bifurcation of the C3 and C4 vertebrae, the septal aperture, the third trochanter, and the anterior and middle calcaneal facets. While the frequencies and the chi-square results of these traits are not enough to be used in isolation, this analysis of a nonmetric postcranial trait list identifies the necessity for further research into these traits and their associations with ancestry estimation.