Skull pneumatization as possible correlate of large CP size; contrast between elephant and gorilla skulls shown in CT scan images and 3D skull models.

(a), Coronal cross-section slice from CT scan of elephant (Loxodonta africana) skull showing ~250 mm pneumatized bone surrounding brain. Scale bar: 100 mm. (b), Dorsal view of elephant skull model. Yellow line: locale of image in (a). Scale bar: 100 mm. (c), Coronal cross-section from CT scan of gorilla (Gorilla gorilla) skull; brain surrounded by non-pneumatized cortical bone. Scale bar: 40 mm. (d), Dorsal view of gorilla skull model. Yellow line: locale of image in (c). Red: CP. 3D models made with Mimics and 3-matic software from high-resolution CT scans.