Hammerhead

Challenges intruders on its territory, especially other hammerheads. Displays its pectoral fins and closes its enamel head shield before attacking.

Spiracles behind the eyes feed into a jet channel with internal gills. The jet drives the hammerhead's sudden rams.

Floats in a protective cyst. The central eye sees color, while two smaller motion-sensitive eyes guide ramming.

The muscular vertical jaw suggests a diet of sponges, kelps, tunicates, and possibly crushed coral. The need to protect a grazing area may have evolved the hammerhead's territoriality.

Hammerheads ram coral domes. The adaptive benefit is unclear—perhaps toughening their shields. Advise caution, especially when piloting vehicles. May have social cognition comparable to Earth’s ungulates, some of which were extremely dangerous to humans. Ramming areas (called leks) are a major source of ocean noise.