found: Tibbitts, Christiane Kump, 1953- Seashells, crabs, and sea stars, 1996(DLC)95024501
found: ITIS, December 11, 2021(Echinodermata; Taxonomic rank: Phylum; Common name: echinoderms; Kingdom: Animalia)
found: Britannica, viewed December 9, 2021(echinoderm, any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard, spiny covering or skin. Living representatives include the classes Crinoidea (sea lilies and feather stars), Echinoidea (sea urchins), Holothuroidea (sea cucumbers), Asteroidea (starfishes, or sea stars), Ophiuroidea (basket stars and serpent stars, or brittle stars), and Concentricycloidea (sea daisies; discovered in the 1980s))
found: Merriam Webster, viewed December 9, 2021(echinoderm: any of a phylum (Echinodermata) of radially symmetrical coelomate marine animals including the starfishes, sea urchins, and related forms)
