Shell turtles are a type of turtle that have a hard outer shell, or CARAPACE, which is made up of plates of bone covered in a layer of keratin. This shell provides protection from predators and the environment. Shell turtles come in a variety of sizes and colors, and can be found in many parts of the world. They are omnivorous, meaning they eat both plants and animals. Shell turtles are an important part of the ecosystem, as they help to keep the food chain in balance.