Differences in the Shape of the Frontal Bone between 20th-Century Euro-Americans and Germans

Geometric morphometrics is a very useful but rarely applied concept in forensic anthropology. It uses information on the shape of an object for data analysis. For this study, geometric morphometrics has been used to compare the shape of the frontal bone between a German and a Euro-American sample (both early 20th century). Results were compared using size-only, shape-only and size-and-shape combined. Results show that the frontal shapes of the two study populations can clearly be distinguished from one another. The best classification results could be achieved when combining size and shape data for analysis. Centroid size showed significant variation by group and sex, and that Euro-Americans are more sex dimorphic than Germans. We conclude that shape data provides a considerable amount of extra information for population affinity estimation, even on a single cranial bone like the frontal. A broader application of geometric morphometrics in forensic anthropology could thus help generating a more reliable biological profile, as well as providing additional insight into German-American morphometric differentiation.