Superior view of middle and posterior cranial fossae. The middle fossa is bounded anteriorly by the lesser wings of the sphenoid and posteriorly by the petrous portion of the temporal bone. The posterior fossa is bounded anteriorly by the dorsum sellae, the petrous portion of temporal, and the transverse groove of the occipital bone. The sella turcica consists of the tuberculum sellae, hypophyseal fossa, and dorsum sellae. The greater wing of the sphenoid contains the foramen rotundum, foramen ovale, and foramen spinosum. Between the lesser and greater wings are the superior orbital fissures. The foramen lacerum is a space bounded by the body of sphenoid, greater wing of sphenoid, and apex of petrous bone. The different parts of the temporal bone are visualized. The jugular foramen is a space between the petrous bone and occipital bone. Posterior to the foramen magnum is the internal occipital crest for attachment of the falx cerebelli with its groove for the occipital sinus. It ends superiorly at the cruiciform eminence. An either side of the crest are the cerebellar fossae. (Image courtesy of AL Rhoton, Jr.)