any of the Echinodermata, a phylum of marine animals such as starfishes, sea urchins, sea cucumbers, etc., having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines.
any of the Echinodermata, a phylum of marine animals such as starfishes, sea urchins, sea cucumbers, etc., having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines.