1. The family Sphyrnidae comprises nine species: the winghead (Eusphyra blochii); the scalloped bonnethead (Sphyrna corona); the whitefin hammerhead (Sphyrna couardi); the scalloped hammerhead (Sphyrna lewini); the scoophead (Sphyrna media); the great hammerhead (Sphyrna mokarran); the bonnethead (Sphyrna tiburo); the smalleye hammerhead (Sphyrna tudes); and the smooth hammerhead (Sphyrna zygaena).

2. The family Sphyrnidae comprises nine species: the winghead (Eusphyra blochii); the scalloped bonnethead (Sphyrna corona); the whitefin hammerhead (Sphyrna couardi); the scalloped hammerhead (Sphyrna lewini); the scoophead (Sphyrna media); the great hammerhead (Sphyrna mokarran); the bonnethead (Sphyrna tiburo); the smalleye hammerhead (Sphyrna tudes); and the smooth hammerhead (Sphyrna zygaena