Ancestry Determination from the Cranial Base Angle

Abstract

The forensic identification of a set of human remains begins by creating a biological profile. A biological profile is an estimation of sex, age-at-death, stature and ancestry of the individual. This study analyzes the cranial base angle, located at the base of the skull, to address the question of ancestry. The midface region of the skull is most popularly used for ancestry determination, though it is made of fragile bone and is often not intact in archaeological settings. To most accurately determine ancestry from skeletal features of the midface a whole intact skull is required. Needing a whole skull makes it challenging to accurately determine ancestry from fragmented remains. The correct identification of an individual based on skeletal remains is dependent on all of the information gathered from the remains, ancestry included. This study of the cranial base angle was performed to demonstrate the cranial base’s potential to be an alternative region to the midface for ancestry determination. To perform this study a sample of crania was digitized with the assistance of the JPAC-CIL staff and facility under the mentorship of forensic anthropologist Dr. Joseph T. Hefner. A digitizer was used to gather 3D (X,Y,Z) coordinate data of cranial landmarks. The coordinate data was used to calculate the degree of the angle as well as look at the variation between represented ancestry groups. Further study of the cranial base has the potential to greatly improve ancestry determination, and identification, of fragmented skeletal remains.