The basilar part of occipital bone is located directly posterior towards the body of the sphenoid in the midline. It spreads out posteriorly towards the foramen magnum and via the temporal bones is bounded laterally. The pharyngeal tubercle is protuberant on the basilar portion of the occipital bone and is a bony protrusion for the connection of parts of the pharynx towards the base of the skull.
It is a broad bar of bone which articulates in front with the body of sphenoid in order to create the basisphenoid joint that is a basic cartilaginous joint and is located in front of the foramen magnum.
- The upper surface of the basisphenoid has a superficial channel going from dorsum sellae towards the foramen magnum that slopes downwards as well as backwards. It is referred to as clivus.
- The inferior surface of the basilar portion, approximately 1 cm facing the foramen magnum has a pharyngeal tubercle within median plane.
The basisphenoid joint controls the growth of the skull lengthwise.