These creatures live in the marine environment and their outer layer is composed of a hard and spiky structure or skin. Echinoderms have been around since the middle ages. They have been recognized as part of the phyla in the animal kingdom as the Radiata. These animals have over 21 classes and are composed mainly of a skeletal type structure. Echinoderms can grow up to 10 cm today as a max amount and there is great diversity in the entire species of this organism. They are radially symmetrical as well.
Ex. Starfish and sea-urchins make up most of the echinoderms species.
Ex. Starfish and sea-urchins make up most of the echinoderms species.