Alligator Exoccipital

The exoccipital is a complicated element forming the caudolateral portion of the braincase. It is perforated by numerous cranial nerves and vessels while serving as the attachment of numerous muscles. It forms the rim of the foramen magnum and is pierced caudally by cranial nerves IX, X, XI and XII as well as the jugular vein. The carotid artery enters the cranial cavity via a passage through the exoccipital. The tapering paroccipital process is the attachment for epaxial (neck) muscles as well as for the depressor mandibulae muscle, which opens the jaws. The rostral surface of the element is excavated by portions of the inner and middle ear cavities and its rostrolateral surface has a prominent groove for the passage of the stapedial artery into the middle ear through the cranioquadrate canal.