Alternate name for the basisphenoid, especially when fused with the alisphenoid and pterygoids.

adjective, Greek sphen = wedge, and eidos = shape or form; hence the unpaired bone which is wedged into the base of the skull between the unpaired frontal and occipital.

butterfly-shaped bone at the base of the skull

(G. sphen, wedge + G. eidos, form). Wedge-shaped.

(G. sphen, wedge, + eidos, resemblance). Os sphenoidale.

Anterior to the temporal bones and forms the base of cranium - behind the orbitals. Consists of a body, two "wings" and two "pterygoid processes" (not labelled on diagrams) that project downwards. Articulates with the frontal, parietal and temporal bones.

Wedge-shaped; designating, especially, a very irregular wedge-shaped bone at the base of the skull.