Marine coelomate animals distinguished from all others by an internal skeleton composed of calcite plates, and a water-vascular system to serve the needs of locomotion, respiration, nutrition or perception.
A phylum of marine animals found at all ocean depths. The phylum appeared near the start of the Cambrian period, and contains about 7,000 living species,
marine invertebrates with tube feet and calcite-covered five-part radially symmetrical bodies
marine invertebrates with tube feet and five-part radially symmetrical bodies
