Which shark species is the type species of the genus Sphyrna?

The smooth hammerhead is the type species of the genus Sphyrna.

Its scientific name is Sphyrna zygaena, and Carl Linnaeus described it in 1758. In biological nomenclature, a type species is the species permanently linked to a genus name for classification purposes. Because Sphyrna was established around this species, the smooth hammerhead anchors the genus’s identity.

The name “smooth” refers to the front edge of its broad, flattened head, or cephalofoil. Unlike several related hammerheads, it lacks a central notch in that margin. The genus name Sphyrna comes from the Greek word for “hammer,” describing the distinctive head shape shared by its members.

The smooth hammerhead is often confused with the great hammerhead and scalloped hammerhead. The great hammerhead usually has a pronounced central notch and a taller dorsal fin, while the scalloped hammerhead has a scalloped indentation along the front of its head. The bonnethead is also a Sphyrna species, but it has a much smaller, shovel-shaped head.