69(Y3) Assembling fossil cranial fragments based on local shape information

• Published in: Anthropological Science Vol. 119; no. 3; p. 291
• Main Authors: KIKUCHI T, OGIHARA N, SUZUKI H, MICHIKAWA T, KONDO O, ISHIDA H, AKAZAWA T
• Format: Journal Article
• Language: Japanese
• Published: Anthropological Society of Nippon 2011
• ISSN: 0918-7960

Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is therefore necessary to correctly assemble the fragments. In this study, we developed a computerized technique for assembling fossil cranial fragments based on local shape information, i.e., the smoothness of the joints between fragments. We approximated the surface of each of cranial fragments using Bezier surface to mathematically predict shape of adjacent fragments and their anatomical positions and orientations were calculated. Using this technique, we attempted a new reconstruction of Amud 1 cranium. Specifically, we assembled right and left sides of the cranium separately based on the above mentioned technique, and then put the right and left parts together mathematically based on smoothness of the joint, bilateral symmetry and the distance between the mandibular fossae determined from the associated undeformed mandible. As a result, smooth yet globally consistent assembly of the fragments of Amud 1 cranium became possible. Although some methodological limitations certainly apply, the proposed method may serve as an effective tool to aid objectively assembling fossil cranial fragments.