Sphenoidal emissary foramen

In the base of the skull, in the great wings of the sphenoid bone, medial to the foramen ovale, a small aperture, the sphenoidal emissary foramen, may occasionally be seen (it is often absent) opposite the root of the pterygoid process. When present, it opens below near the scaphoid fossa. Vesalius was the first to describe and illustrate this foramen, and it thus sometimes bears the name of foramen Vesalii (meaning foramen of Vesalius). Other names include foramen venosum and canaliculus sphenoidalis.