Inferior view of the posterior aspect of the skull. In this enlarged perspective, most of the foramen magnum, the largest foramen in the skull, is in view in the lower central part of the image. Anterior to its margin is the clivus, a bony slope directed towards the body of the sphenoid. At its upper lateral margin is the foramen lacerum, bounded by the clivus, the greater wing of the sphenoid, and the apex of the petrous portion of the temporal bone. This foramen is filled in life by fibrous cartilage. In the posterior portion of the greater wing are the foramen ovale and the foramen spinosum. Anterolateral to the foramen magnum are the large occipital condyles that articulate with the superior articular processes of the atlas. Lateral to these are the jugular foramina, spaces between the petrous bone and the occipital bone. Just anterior to a jugular foramen is the opening of the carotid canal within the petrous bone. The styloid process of the right temporal bone can be see in this specimen near the left border of the image. Beneath the occipital condyles are canals, the hypoglossal canals, for transmission of the hypoglossal nerves. (Image courtesy of AL Rhoton, Jr.)