Osseous anatomy of the posterior skull base. Ventral view of the occipital bone. The clival portion is narrow superiorly but widens inferiorly as the lateral or condylar portion incorporates to the occipital bone. The exocranial opening of the hypoglossal canal is located above the occipital condyle. The jugular tubercle cannot be seen from the ventral perspective, but it is located in the lateral portion of the occipital bone, above the hypoglossal canal. The jugular foramen is located lateral to the hypoglossal canal, and the jugular process forms the floor of the jugular foramen. The condyles are located in the anterolateral aspect of the foramen magnum. (Image courtesy of JC Fernandez-Miranda)