Loggerhead sea turtles are known for their massive heads, strong jaws, and reddish-brown heart-shaped shells. Loggerheads are primarily carnivores, using their strong jaws to crush invertebrates such as conchs, bivalves, and horseshoe crabs. The Loggerhead is considered a “keystone species,” which means that other animals in its ecosystem depend on it for survival as they help to maintain balance and support biodiversity.