Exoskeleton

An exoskeleton (From Greek ἔξω, éxō = “outer” + σκελετός, skeletos = “skeleton”) is the external skeleton that supports and protects an animal’s body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as “shells”. Examples of exoskeleton animals include insects such as grasshoppers and cockroaches, and crustaceans such as crabs and lobsters.