The bonnethead (Sphyrna tiburo), also called a bonnet shark or shovelhead, is a small member of the hammerhead shark genus Sphyrna, and part of the family Sphyrnidae. It is an abundant species in the littoral zone of the North Atlantic and the Gulf of Mexico, is the only shark species known to display sexual dimorphism in the morphology of the head, and is the only shark species known to be omnivorous.