List of echinoderm orders

=== Class Crinoidea === • Subclass Articulata (540 species) • Order Bourgueticrinida • Order Comatulida • Order Cyrtocrinida • Order Hyocrinida • Order Isocrinida • Order Millericrinida • Subclass †Flexibilia • Subclass †Camerata • Subclass †Disparida Image:Comaster schlegelii.JPG|Comaster schlegelii (Comatulida) Image:Holopus 2.jpg|Holopus sp. (Cyrtocrinida) Image:Encrinus liliiformis 4.JPG|Encrinus liliiformis (Encrinida) Image:Calamocrinus diomedæ (Plate XXVIII) BHL4232451.jpg|Calamocrinus diomedae (Hyocrinida) Image:Proisocrinus ruberrimus.jpg|Proisocrinus ruberrimus (Isocrinida) Image:Liliocrinus polydactylus MHNT.jpg|Liliocrinus polydactylus === Class Paracrinoidea † === No orders, 13 to 15 genera are known. • order Comarocystitida † • ?Family Heckeritidae † • Heckerites † • Family Amygdalocystitidae † • Achradocystites † Volborth, 1870 • Amygdalocystites † Billings, 1854 (= Ottawacystis) (?= Billingsocystis) • Oklahomacystis † Parsley & Mintz, 1975 (Bassler, 1943) • Ovulocystites † Frest et al., 1980 • Family Comarocystitidae † Balther, 1899 • Comarocystites † Billings, 1854 • Implicaticystis † • Sinclairocystis † • order Platycystitida † • Family Platycystitidae † • Canadocystis † (= Sigmacystis) • Platycystites † • Family Malocystitidae † • Malocystites † • Wellerocystis † • Family Bistomiacystitidae † • Bistomiacystis † Doubtful paracrinoids: • Columbocystis • Foerstecystis • Springerocystis • Ulrichocystis • Paleocystites • Allocystites === Class Cystoidea === • order Aristocystitida • order Asteroblastida • order Glyptosphaeritida • order Sphaeronitida === Class Edrioasteroidea † === '' (Edrioasteroidea) • order Edrioasterida • order Isorophida == Subphylum Asterozoa ==

=== Class Ophiuroidea (Brittle stars) === • order Euryalida • order Ophiurida • order Amphilepidida • order Ophiacanthida • order Ophioleucida • order Ophioscolecida Image:Basket star feeding at night at the Red Sea.JPG|Astroboa nuda (Euryalida) Image:Ophiura ophiura.jpg|Ophiura ophiura (Ophiurida) Image:Ophiolepis elegans 600.jpg|Ophiolepis elegans (Amphilepidida) Image:Ophiure noire à la Réunion.JPG|Ophiocoma erinaceus (Ophiacanthida) Image:Ophioleuce seminudum (MNHN-IE-2013-10292) 02.jpg|Ophioleuce seminudum (Ophioleucida) Image:Ophiomyces frutectosus (MNHN-IE-2013-10282) 02.jpg|Ophiomyces frutectosus (Ophioscolecida) === Class Asteroidea (Starfish) === • Infraclass Concentricycloidea • Peripodida • Superorder Forcipulatacea • Brisingida • Forcipulatida • Superorder Spinulosacea • Spinulosida • Superorder Valvatacea • Notomyotida • Paxillosida • Valvatida • Velatida • † Calliasterellidae • † Trichasteropsida Image:Xyloplax janetae.jpg|Xyloplax janetae (Peripodida) Image:Brisingid Seastar (Novodinia antillensis).jpg|Novodinia antillensis (Brisingida) Image:Starfish, Oregon coast.jpg|Pisaster ochraceus (Forcipulatida) Image:Echinaster sepositus Banyuls 03.jpg|Echinaster sepositus (Spinulosida) Image:Cheiraster echinulatus.jpg|Cheiraster echinulatus (Notomyotida) Image:Astropecten aranciacus Sardegna09 28cm 5520.jpg|Astropecten aranciacus (Paxillosida) Image:Linckia laevigata Tonga.jpg|Linckia laevigata (Valvatida) Image:Euretaster insignis.jpg|Euretaster insignis (Velatida) == Subphylum Echinozoa ==

=== Class Echinoidea (Sea urchins) === , a well-armoured sea urchin • Superorder Diadematacea • Order Diadematoida • Order Echinothurioida • Order Pedinoida • Superorder Echinacea • Order Arbacioida • Order Echinoida • Order Phymosomatoida • Order Salenioida • Order Temnopleuroida • Superorder Gnathostomata • Order Clypeasteroida (sand dollars) • Order Holectypoida • Superorder Atelostomata • Order Holasteroida • Order Spatangoida (heart urchins) Image:Aspidodiadema arcitum.jpg|Aspidodiadema hawaiiense, an Aspidodiadematoida Image:Diadema antillarum Flower Garden Banks.jpg|Diadema antillarum, a Diadematoida Image:Caenopedina hawaiiensis.jpg|Caenopedina hawaiiensis, a Pedinoida Image:Salenocidaris hastigera.png|Salenocidaris hastigera, a Salenioida Image:Arbacia lixula (oursin noir).JPG|Arbacia lixula, an Arbacioida Image:Strongylocentrotus franciscanus at Telegraph Cove.jpg|Strongylocentrotus franciscanus, a Camarodonta Image:S. variolaris.jpg|Stomopneustes variolaris, a Stomopneustoida Image:Toxic Leather Sea Urchin - Asthenosoma marisrubri.jpg|Asthenosoma marisrubri, an Echinothurioida Image:Pourtalesia wandeli.png|Pourtalesia wandeli, a Holasteroida Image:Tiny maretia heart urchin (Maretia planulata).jpg|Maretia planulata, a Spatangoida Image:Echinoneus cyclostomus.jpg|Echinoneus cyclostomus, an Echinoneoida Image:Clypeaster reticulatus.jpg| Clypeaster reticulatus, a Clypeasteroida Image:Echinolampas depressa.png|Echinolampas depressa, an Echinolampadoida Image:Eucidaris metularia à la Réunion.jpg|Eucidaris metularia, a Cidaroida === Class Holothuroidea (Sea cucumbers) === • Order Apodida • Order Dendrochirotida • Order Elasipodida • Order Holothuriida • Order Molpadida • Order Persiculida • Order Synallactida Image:Euapta godeffroyi1.jpg|Euapta godeffroyi (Apodida) Image:Cercodemas anceps Red box sea cucumber PC260152.JPG|Cercodemas anceps (Dendrochirotida) Image:Scotoplanes globosa and crab.jpg|Scotoplanes globosa (Elasipodida) Image:Holothuria cinerascens Réunion.jpg|Holothuria cinerascens (Holothuriida) Image:See-through sea cucumber (Paracaudina australis).jpg|Paracaudina australis (Molpadida) Image:Hansenothuria benti.png|Hansenothuria benti (Persiculida) Image:Stichopus herrmanni (Mayotte).jpg|Stichopus herrmanni (Synallactida) === Class Ophiocistioidea † === '' 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. === Class Helicoplacoidea † === No known orders, 2 known species, Helicoplacus curtisi and H. guthi == Subphylum Blastozoa ==

=== Class Blastoidea † === • Order Coronata † • Order Fissiculata † • Order Spiraculata † • basal Macurdablastus † === Class Eocrinoidea † === '' (Eocrinoidea) • Order Ascocystida † • Order Gogiida † • Order Imbricata † • Order Trachelocrinida † == Subphylum Homostelea / Homalozoa † ==

'', a Stylophora. === Class Ctenocystoidea † === • order Ctenocystida † === Class Soluta † === === Class Cincta † === === Class Stylophora † === • order Cornuta † • order Mitrata † == References ==