List of echinoderm orders

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

Subphylum [Crinozoa]

Class [Crinoidea]

Subclass Articulata

* Order Bourgueticrinida
* Order Comatulida
* Order Cyrtocrinida
* Order Hyocrinida
* Order Isocrinida
* Order MillericrinidaSubclass †FlexibiliaSubclass †CamerataSubclass †Disparida

Class [Paracrinoid]ea †

No orders, 13 to 15 genera are known.

order Comarocystitida †
* ?Family Heckeritidae †
** Heckerites †
* Family Amygdalocystitidae †
** Achradocystites † Volborth, 1870
** Amygdalocystites † Billings, 1854
** Oklahomacystis † Parsley & Mintz, 1975
** Ovulocystites † Frest et al., 1980
* Family Comarocystitidae † Balther, 1899
** Comarocystites † Billings, 1854
** Implicaticystis †
** Sinclairocystis †
order Platycystitida †
* Family Platycystitidae †
** Canadocystis †
** Platycystites †
* Family Malocystitidae †
** Malocystites †
** Wellerocystis †
* Family Bistomiacystitidae †
** Bistomiacystis †

Doubtful paracrinoids:ColumbocystisFoerstecystisSpringerocystisUlrichocystisPaleocystites

''Allocystites''

Class Cystoidea">Cystoids">Cystoidea

order Aristocystitida
order Asteroblastida
order Glyptosphaeritida
order Sphaeronitida

Subphylum [Asterozoa]

Class Ophiuroidea ([Brittle star]s)

order Euryalida
order Ophiurida
order Amphilepidida
order Ophiacanthida
order Ophioleucida
order Ophioscolecida

Class Asteroidea ([Starfish])

Infraclass Concentricycloidea
*Peripodida
Superorder Forcipulatacea
*Brisingida
*Forcipulatida
Superorder Spinulosacea
*Spinulosida
Superorder Valvatacea
*Notomyotida
*Paxillosida
*Valvatida
Velatida
† Calliasterellidae
† Trichasteropsida

Subphylum [Echinozoa]

Class Echinoidea ([Sea urchin]s)

Superorder Diadematacea
* Order Diadematoida
* Order Echinothurioida
* Order Pedinoida
Superorder Echinacea
* Order Arbacioida
* Order Echinoida
* Order Phymosomatoida
* Order Salenioida
* Order Temnopleuroida
Superorder Gnathostomata
* Order Clypeasteroida
* Order Holectypoida
Superorder Atelostomata
* Order Holasteroida
* Order Spatangoida

Class Holothuroidea ([Sea cucumber]s)

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