sclerite

The word sclerite comes from the Greek skleros, meaning "hard." In biology, it refers to a hardened body part, usually one of the plates or pieces that make up a skeleton or outer body covering. The term is used most often for invertebrates rather than vertebrates.

You'll see it most clearly in arthropods, including insects, spiders, and crustaceans. Their exoskeleton is not always one smooth shell. Instead, it is often divided into separate hard plates linked by softer, flexible tissue. Those plates are sclerites. This design gives the animal two useful things at once: protection from the outside and enough flexibility to move its legs, wings, or body segments.

The term also appears in marine biology. Soft corals, for example, contain tiny hard pieces in their tissues, and these can also be called sclerites. In that setting, the word still points to the same basic idea: a small hardened skeletal element that adds support, protection, or structure.

Sclerites are also important in paleontology. Hard parts are much more likely to survive in the fossil record than soft tissue, so isolated plates and fragments can be the best clues scientists have. By studying their shape, size, and pattern, researchers can learn how an animal's body was built and sometimes even how it lived. So although the word sounds technical, its meaning is quite practical: it names one of the hard pieces that help form an animal's protective or supporting framework.