Virtual Endocast of Qafzeh 9: A Preliminary Assessment of Right-Left Asymmetry

Abstract

We performed a semi-virtual reconstruction of the endocast for Qafzeh 9, a representative of early anatomically modern humans in the Near East, by using sequential CT images of the present cranial reconstruction with manual clay infilling of the gap and missing portions in the inner cranial surface. After assessing the reconstructed virtual endocast in terms of right-left (R-L) asymmetry, we morphed it in such a manner that the observed asymmetry reduced and fit into the range of variation observed in recent humans. The assessment suggests that the present reconstruction of the Qafzeh 9 cranium, possessing a significant degree of R-L asymmetry, suffers from distortion. Directly measured endocranial volumes (1411 cc for the original reconstruction and 1477 cc for the morphed version) were smaller than previously published data (1531 cc) using least-square regression equations. After morphing, the endocast was higher at the middle cranial fossa and narrower at the frontal lobe, both characteristics falling within the range of recent human variation. Although the reconstructed Qafzeh 9 endocasts of both the original and morphed versions fit into the endocranial evolution among lineages of the genus Homo, many fossil crania may have undergone a substantial degree of taphonomic deformation. Therefore, application of possible corrections or hypothesis of plausible taphonomic scenarios should be part of a reasonable assessment of a single precious fossil specimen.