Anterior inferior view of skull base. In this specimen, the clivus and body of the sphenoid occupy the midline. The sphenoid sinus is exposed. The lesser and greater wings of the sphenoid can be observed as well as the superior orbital fissure, the space between them. Inferolateral to the sphenoid body descend the pterygoid processes, which give rise to lateral and medial pterygoid plates. The foramen rotundum and pterygoid canal open on the anterior superior surface of each pterygoid process which serves as the posterior boundary of the pterygopalatine fossa. The lateral pterygoid plate serves as the medial boundary of the infratemporal fossa and these two fossae communicate via the pterygomaxillary fissure. Posteriorly, the jugular foramen can be seen as a space between the occipital bone and the petrous portion of the temporal. (Image courtesy of AL Rhoton, Jr.)