To about 12 ft (3.7 m).
- Head broadly arched and hammer-shaped, marked by prominent indentation at midline ("scalloped")
- Pelvic fins with straight rear margins
- Color deep olive to brownish-gray above, shading to white below
- No interdorsal ridge
Massachusetts to Brazil, including Gulf of Mexico and Caribbean Sea.
Coastal and offshore, primarily in water >72°F (22°C); coastal bays and surface waters to at least 900 ft (274 m).
Bonnethead has shovel-shaped head; growns to about 5 ft (1.5 m). Smooth Hammerhead lacks central indentation on anterior margin of head. Great Hammerhead attains larger maximum size (18.5 ft (5.6 m)); has very high first dorsal fin, pelvic fins with curved rear margins.
Text descriptions taken from:
Guide to Sharks, Tunas, & Billfishes
of the U.S. Atlantic and Gulf of Mexico