Exoskeleton

An exoskeleton refers to the chitinous or calcified external skeleton used by numerous animal taxa for structural support and defense against predators.

Exoskeletons can be contrasted with endoskeletons (internal skeletons) that humans and other vertebrates have.

In the animal world, exoskeletons are much more common than endoskeletons -- millions of species have exoskeletons, while only a few thousand have endoskeletons.

Exoskeletons are especially popular among arthropods and mollusks, two of the largest animal phyla in existence.

Check for a few common examples of exoskeleton !