Covariance Among Zygomatic Bone Shape, Eye Orbit Shape, and the Zygomaticotem-Poral Space
American Journal of Physical Anthropology
First page number:
The unique position of the zygomatic bone in both hominins and non-hominin primates has remained a focus of research for decades. Because of the unique position of the zygomatic bone, as connected to both the face and cranium, especially the eye orbit, evolutionary changes to this one might be indicative of other adaptive responses other than those involved in mastication. The zygomatic bone makes up a significant portion of the eye orbit with implications for vision, but also makes up a significant portion of the zygomaticotemporal space, with implications for mastication. Since both of these functions require a specific shape and structure of the zygomatic bone, we hypothesize that there might be constraints due to functional relationships. In order to examine these relationships, to determine if the different anatomical uses of the zygomatic bone are constrained and/or independent of each other, 28 different facial landmarks were collected from humans, fossil hominins, chimpanzees, and gorillas using CT scans and the data collection software Checkpoint. For this study, specific hypotheses include 1. that the shape of the zygomaticotemporal space covaries with orbit shape, 2. that zygomaticotemporal space covaries with zygomatic thickness, and 3. that the eye orbit covaries with zygomatic thickness. Results indicate that there is a relationship between the zygomaticotemporal space, the eye orbit, and the thickness of the zygomatic bone, suggesting that the zygomatic reflects functional constraints associated with surrounding anatomy.
Biological and Physical Anthropology
Covariance Among Zygomatic Bone Shape, Eye Orbit Shape, and the Zygomaticotem-Poral Space.
American Journal of Physical Anthropology, 168(S68),