Figure 8.

Thin plate spline deformations representing the foramen magnum shape change along the first three principle components. The principle components analysis was performed on the sample of 152 foramina from crania with known diversity of geography, age, and sex-having no apparent bony pathology. Collectively, the first three principle components account for 66.69% of the total shape variance (principle component 1 = 37.95%; principle component 2 = 17.45%; and principle component 3 = 11.3%)