Noun
cephalofoil (plural cephalofoils)
(zoology) Either of the two outward extensions of the head of a hammerhead shark.
The hammerhead sharks are a group of sharks in the family Sphyrnidae, so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Source: Internet
Many not necessarily mutually exclusive functions have been proposed for the cephalofoil, including sensory reception, manoeuvering, and prey manipulation. Source: Internet