overlaps overlaps develops from composed primarily of sphenoid bone http://upload.wikimedia.org/wikipedia/commons/6/66/Illu_cranial_bones2.jpg UMLS:C0037884 os sphenoidum sphenoid complex part of viscerocranium (facial skeleton) in FMA uberon FMA:52736 os sphenoidale UBERON:0001677 MESH:D013100 sphenoidal bone NCIT:C12790 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. os sphenoidale GAID:230 sphenoid EMAPA:18340 CALOHA:TS-2343 butterfly bone MA:0001472 chondrocranium bone tissue endochondral bone dermatocranium facial bone pneumatized bone splanchnocranium sphenoid cartilage element sphenoid endochondral element