A Morphometric Examination of Cranial Vault Modification in the Middle Cumberland Region of Central Tennessee

Cranial vault modification (CVM) is a physical manifestation of intersections between culture and biology. Cultural practices that apply pressure to the head during infancy result in significant reshaping of the skull and can be either intentional or unintentional. Occipital flattening is present among many Mississippian skeletal samples from the Middle Cumberland Region (MCR) of central Tennessee and is thought to be an unintentional result of childcare practices. Traditional methods for CVM classification have concentrated on visual assessment of location and means of flattening; however, this method is subjective. This thesis seeks to evaluate visual assessment of CVM through a morphometric analysis of cranial landmarks using 3D scanning technology. The hypothesis tested is that shape differences among MCR crania correspond to visual assessment of CVM presence. Additionally, morphological variation in cranial shape is examined for sex differences that may correspond to differential cultural practices performed on males and females. Finally, differences in cranial shape variation by site are tested to determine if CVM practices differed within the MCR.

This thesis examines CVM within the Arnold (n=23), Bowling Farm (n=14), and Averbuch (n=47) Mississippian skeletal samples from the MCR. Landmark coordinate data is extracted generated from high-resolution 3D models of MCR crania. A principal components analysis is performed to examine the magnitude and directionality of changes in landmark distributions among individuals. Additionally, discriminant function analysis (DFA) and canonical variate analysis (CVA) is employed in order to evaluate whether variation in cranial landmark locations corresponds with modified and unmodified categories determined by visual assessment, sex, or site membership.

Results indicate that morphological variation exhibited by MCR crania largely correspond to categories determined by visual assessment of CVM. Additionally, there is no morphological distinction by sex among modified crania, indicating that CVM practices were not performed differently between males and females in the MCR. Finally, differences in shape variation among MCR sites are demonstrated and archaeological explanations for those differences are explored. The results of this thesis contribute to a larger body of anthropological literature concerned with Mississippian occupation of the MCR, for which no ethnographic evidence exists.