The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)

Demographic parameters of commingled skeletal samples


1Anthropology Program, Bioanthropology Research Institute, Quinnipiac University, 2Department of Anthropology, University of Notre Dame

March 27, 2015 11:30, Grand Ballroom C Add to calendar

Published studies of commingled skeletons frequently omit demographic information from analysis, citing the inability to age fragmentary, mixed bones. While discrete individuals typically cannot be evaluated from commingled collections, general patterns of age should be considered when comparing two or more samples. This is particularly important for studies assessing pathological conditions or other alterations to the skeleton. Distribution of phase assignments (instead of ages derived from phases) can provide insight into general demographic changes in commingled samples. This technique was applied to skeletal collections from two time periods from the Early Bronze Age site of Bab adh-Dhra’, Jordan (ca. 3500-2010 BCE). Aging techniques included cranial suture closure and pubic symphysis and auricular surface changes in adults, as well as metric examination of subadult femora, occipitals, and ischia. In general, there was no significant difference between Early Bronze IA (3500-3300 BCE) and Early Bronze II-III (3100-2300 BCE) adults. Right auricular surfaces exhibited no difference (Mann-Whitney U=196, n=45, p-0.26), nor did cranial vault suture closure scores (Mann-Whitney U=105.5, n=35, p=0.32). There was a significant difference between measurements of subadult: femoral distal width (right side: Mann-Whitney U=49, n=38, p<0.001), basilar sagittal length (Mann-Whitney U=329.5, n=79, p<0.001), and left ischial width (Mann-Whitney U=55, n=30, p=0.033). The difference in subadults was due to the presence of more perinates and infants in Early Bronze IA. General patterns of age proxies can contribute to our understanding of demography in commingled collections, and should be considered in any bioarchaeological study.

This work was funded by NSF-REU (SES9649088) at the University of Notre Dame, Ohio State University, Smithsonian Institution, Sigma Xi, and Notre Dame’s Institute for Scholarship in the Liberal Arts.