An unpaired bone situated at the base of the skull in front of the temporal bone and basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended. [ http://en.wikipedia.org/wiki/Sphenoid_bone ]

Synonyms: os sphenoidale sphenoidal bone sphenoid