An echinoderm is any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard spiny covering or skin. This is a list of significant echinoderms grouped by subphylum and ordered alphabetically followed by a list of extinct echinoderms grouped alphabetically by class. (See also invertebrate.)

subphylum Asterozoa

• brittle star (class Ophiuroidea)
• sea star (class Asteroidea)

  • crown-of-thorns starfish (Acanthaster planci)

subphylum Crinozoa

• crinoid (class Crinoidea)

  • feather star (order Comatulida)
  • sea lily (order Bourgueticrinida)

subphylum Echinozoa

• sea cucumber (class Holothuroidea)
• sea urchin (class Echinoidea)

  • cake urchin and sand dollar (order Clypeastroida)
  • heart urchin (order Spatangoida)

extinct echinoderms

• blastoid (class Blastoidea)

  • genus Cryptoblastus
  • genus Pentremites
• carpoid (class Carpoidea)
• crinoid (class Crinoidea; many extant species)

  • genus Cyathocrinites
  • genus Platycrinites
• cystoid (class Cystoidea)

  • genus Echinosphaerites
  • sea urchin (class Echinoidea; many extant species)

    • genus Holectypus