Human Bones of the Latest Jomon Period Hobi Shell Mound "Banjo-shuseki" Burials:

A Study of Bone Compositions and Morphological Characteristics

Abstract

In order to discuss the characteristics and the significance of the "Banjo-shuseki" burials of the latest Jomon period, two assemblages of the Hobi shell mound, Aichi Prefecture, were investigated. These consisted of 87 (Shuseki-1) and 52 (Shuseki-B) human bone specimens. Element compositions, minimum number of individuals, and age representation of the Banjo-shuseki remains were determined. Sex composition was estimated from femurs, which were the most numerous element in each of the Banjo-shuseki burials. In determining sex, we constructed discriminant functions from femoral metric data of the individually buried human skeletons from the same Hobi site, for which reliable sex identification was possible from sufficiently preserved innominate bones. We then applied the functions to the Banjo-shuseki human femurs. We found that, in particular, femoral cortical area at midshaft was an excellent indicator of sex. Bone element compositions of the Hobi Banjo-shuseki burials were biased toward a higher representation of the lower limb bones. The number of individuals included was determined to be more than 14 in the Shuseki-1 burial (4 adult male, 6 adult female, 1 adult sex-unknown, 3 infant/juvenile) and more than 6 in the Shuseki-B burial (3 adult male, 2 adult female, 1 infant/juvenile). The morphological characteristics and mechanical robusticity of the Banjo-shuseki skeletal remains were compared with the condition seen in the individual burials from the same Hobi site. We focused on the femur, for which a sufficient number of specimens enabled statistical comparisons. In males, a significant difference was found in the pilasteric index between the Banjo-shuseki and individual burial remains, the former characterized by an extreme degree of pilaster development. Otherwise, in both sexes, significant differences were not found between burial types, either in femoral size or midshaft robusticity. The known bias in temporal and regional occurrences of the Banjo-shuseki burials and the elemental compositions and relatively large number of individuals represented in the Hobi examples of the present study suggest that these burials were based on intentional re-excavation and re-burial. Several explanations are possible for the prevalence of strongly pilasteric femurs in the Hobi Banjo-shuseki remains. One possibility is that the Banjo-shuseki burials might have been applied to a group of people with specific rank, activity role, or genealogical relationship.