Ethmoturbinal complexity matches large RelCP in African elephant; contrast between turbinal-rich elephant skull and turbinal-depauperate rock hyrax skull shown in CT scan images and 3D skull models.

Ethmoturbinal bones, which carry the olfactory epithelium, are unusually expansive in the African elephant (Loxodont africana). Quantifying turbinal area is beyond the scope of this paper, but here we visually contrast homologous cross-sections through the nasal chamber at the anterior-most extension of the CP in the elephant and its closest living relative, the rock hyrax (Procavia capensis), which has a relatively small CP. (a), Anterolateral view of elephant skull model. Orange plane: locale of image in image (b). Scale bar: 100 mm. (b), Coronal cross-section from CT scan of elephant nasal cavity. Scale bar: 20 mm. Blue: turbinal bones. Red: CP. (c), Hyrax skull model. Scale bar: 10 mm. Orange plane: locale of image in (d). (d), Coronal slice from CT scan of hyrax nasal cavity. Scale bar: 5 mm. Blue: turbinals. Red: CP. 3D models constructed with Mimics and 3-matic software from high-resolution CT scans.