All three have a large muscular foot with which they adhere and crawl over rocks. They have jaws and a scraping device called a radula for feeding on attached algae. Among those that are carnivorous, the radula is modified for drilling through the shells of prey. These animals are oval shaped with the upper surface of the body covered in a series of eight interlocking plates. By means of a muscular foot they adhere and crawl over rock surfaces.
Chitons graze on attached algae that they scrape off with a feeding device called a radula.
Among those that burrow, they have a large foot adapted for burrowing. All are filter feeders. The gills of these animals create a water current that brings water into the shell cavity. Food particles are then trapped and conveyed to the mouth. These animals have an external skeleton.