Provided by Clinic for the Rehabilitation of Wildlife. The loggerhead is the most common sea turtle found in United States coastal waters. They are named for their relatively large heads which support strong, powerful jaws enabling them to feed on hard-shelled prey! Loggerhead sea turtles have a heart-shaped, reddish-brown carapace in adulthood with a yellowish-brown underside. Hatchlings have a dark brown carapace with pale brown flippers and pronounced scutes.