👉 Chitonida is a group of marine animals that are characterized by their spiny, often hard, bodies. These animals include chitons and other echinoderms, which are part of the clade known as the bivalves.
👉 Chitonidae are a group of ancient, extinct, and now extinct marine reptiles that lived during the Mesozoic Era, which spanned from approximately 258 million years ago to 68 million years ago. These creatures were known for their highly specialized body structures, including large jaws and sharp teeth, which allowed them to hunt in various aquatic environments.