External base of the cranium

Term name Layer
1 Incisive canals Layer 1
2 Greater palatine canal Layer 1
3 Choana; posterior nasal aperture Layer 1
4 Petrosphenoidal fissure; sphenopetrosal fissure Layer 1
5 Petro-occipital fissure Layer 1
6 Foramen lacerum Layer 1
7 Lesser palatine canals Layer 1
8 Bony palate Layer 1