Sphyrna (from the Greek word σφυρί "hammer") is a genus of hammerhead sharks with a cosmopolitan distribution in the world's oceans. Members of Sphyrna have a tendency to inhabit coastal waters along the intertidal zone rather than the open ocean, as their prey items such as invertebrates, fish, rays, small crustaceans and other benthic organisms hide in the sands and sediment along these zones. Members of Sphyrna are also known by a large number of synonyms such as Zygaena, Cestracion, and Sphyrichthys. The earliest species described of this genus was Sphyrna zygaena by Carl Linnaeus in 1758, while the newest member Sphyrna gilberti was discovered and described in 2013.