sphenoturbinal

from The Century Dictionary.

• Sphenoidal and turbinated or whorled or scroll-like; sphenoturbinate: specifically applied, conformably with ethmoturbinal and maxilloturbinal, to the sphenoidal spongy bones. See II.
• noun One of the sphenoidal spongy bones; one of a pair of small bones situated in front of the body of the sphenoid, in man at birth solid, nodular, distinct from each other and from the sphenoid, afterward fused with the body of the sphenoid as delicate spongy or scroll-like bones which take part in forming the sphenoidal sinuses. Their homologues in other animals are questionable.