• Kingdom: Animalia
  • Phylum: Echinodermata

Echinoderms are spiny-skinned, exclusively marine, organisms whose bodies can usually be divided into five parts around a central axis. They possess calcareous plates or ossicles, ambulacra (food) grooves and a water vascular system with tube feet. Paleontologists recognize many extinct classes within this phylum. There are five extant (living) classes within the Echinodermata: