Loggerhead sea turtles are known for their giant reddish brown heads. The head helps support powerful jaw muscles that allow the turtles to crush shellfish. Loggerheads eat shellfish, jellyfish, mussels, shrimp, and other marine animals.
One turtle in this picture (bottom) is wearing a National Geographic Crittercam. Crittercams include video cameras and other information-gathering devices. They can be attached to animals without hurting them. Crittercams help scientists study the animals that wear them.