List of echinoderm orders

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A brittle star, Ophionereis reticulata
A sea cucumber from Malaysia
Starfish exhibit a wide range of colours

This List of echinoderm orders concerns the various classes and orders into which taxonomists categorize the roughly 7000 extant species[1] as well as the extinct species of the exclusively marine phylum Echinodermata.

Subphylum Crinozoa[]

Class Crinoidea[]

Crinoid
Haeckel Cystoidea

Class Paracrinoidea †[]

No orders, 13 to 15 genera are known.

  • order †
    • ?Family †
      • †
    • Family †
      • † Volborth, 1870
      • † Billings, 1854 (= Ottawacystis) (?= Billingsocystis)
      • † Parsley & Mintz, 1975 (Bassler, 1943)
      • † Frest et al., 1980
    • Family † Balther, 1899
      • † Billings, 1854
      • †
      • †
  • order †
    • Family †
      • † (= Sigmacystis)
      • †
    • Family †
      • †
      • †
    • Family †
      • †

Doubtful paracrinoids:

  • Columbocystis
  • Foerstecystis
  • Springerocystis
  • Ulrichocystis
  • Paleocystites
  • Allocystites

Class Cystoidea †[]

  • order †
  • order †
  • order †
  • order †

Class Edrioasteroidea †[]

(Edrioasteroidea)

Subphylum Asterozoa[]

Class Ophiuroidea (Brittle stars)[]

See also: List of prehistoric brittle stars

Class Asteroidea (Starfish)[]

Subphylum Echinozoa[]

Class Echinoidea (Sea urchins)[]

Strongylocentrotus purpuratus, a well-armoured sea urchin

Class Holothuroidea (Sea cucumbers)[]

See also: List of prehistoric sea cucumbers

Class Ophiocistioidea †[]

No orders recognized: class is divided up into four families, , , , and . The inclusion of Rhenosquamidae within Ophiocistioidea is doubtful, as the organs identified in fossils of as the characteristic "scaly podia" otherwise diagnostic of ophiocistioids may not, in fact, be such structures.

Class Helicoplacoidea †[]

No known orders, 2 known species, Helicoplacus curtisi and H. guthi

Subphylum Blastozoa[]

Class Blastoidea †[]

Blastoidea

Class Eocrinoidea †[]

(Eocrinoidea)
  • Order †
  • Order Gogiida †
  • Order Imbricata †
  • Order †

Subphylum Homostelea / Homalozoa †[]

, a .

Class Ctenocystoidea †[]

    • order †

Class Soluta †[]

Class Cincta †[]

Class Stylophora †[]

References[]

  1. ^ "Animal Diversity Web - Echinodermata". University of Michigan Museum of Zoology. Retrieved 26 August 2012.
  2. ^ Sweet, Elizabeth (2005-11-22). "Asterozoa: Fossil groups: SciComms 05-06: Earth Sciences". University of Bristol. Archived from the original on 2007-07-14. Retrieved 2008-05-07.
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