Inferior view of bony skull. The mandible has been removed to show the inferior surface and features of the skull in this specimen. Beginning anteriorly, the hard palate consists of the palatine processes of the maxillae and horizontal plates of the palatine bones. Just behind the anterior incisors is the incisive foramen. Medial to the third molars are openings for the greater and lesser palatine foramina. In the central part of the skull is the sphenoid bone. In this view, the foramen ovale and foramen spinosum can be seen. Posterior to the sphenoid bone in the midline is the clivus, which ends at the anterior margin of the foramen magnum. The petrous portion of the temporal bone here presents the opening of the carotid canal. At the junction of the apex of the petrous bone, body of the sphenoid, and greater wing of the sphenoid is the foramen lacerum. Lateral to this foramen is a furrow between the greater wing and the petrous bone called the sulcus tubae to which attaches the cartilaginous part of the pharyngotympanic tube. Posterior to the opening of the carotid canal is the jugular foramen, a space between the petrous bone and occipital bone. Lateral to the jugular foramen is the stylomastoid foramen located at the base of the styloid process between it and the mastoid process. Anterior to the mastoid process is the tympanic part of the temporal bone, which contains the external auditory canal. Anterior to this canal is the mandibular fossa which receives the condyle of the mandible for the temporomandibular articulation. Within the occipital bone is the foramen magnum. Along its lateral border are the occipital condyles for articulation with the atlas. The external occipital protuberance is a small midline projection on the posterior surface of the occipital bone. (Image courtesy of AL Rhoton, Jr.)