#carapace
- Protective shell — A rigid anatomical structure resembling a shield, shell, test, or protective skeletal frame, composed of calcareous, chitinous, or siliceous matter, which partially or fully encloses the body of certain invertebrates (such as some crustaceans, mollusks, or protozoans). It serves an essential function as a predator barrier, structural support for soft tissues, and defense against dehydration.
- Tortoiseshell — A hard, translucent, beautifully mottled yellowish-brown horny substance obtained from the shell of certain sea turtles. Due to its plasticity when heated, it has been used since antiquity in decorative arts for luxury items.