Exclusively marine phylum of animals with generally 5-point radial symmetry
For the fungus, see Echinoderma.
Echinoderms
Temporal range: Cambrian Stage 3–Present[1]
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Extant and extinct echinoderms of six classes: Fromia indica (Asteroidea); Ophiocoma scolopendrina (Ophiuroidea); Stomopneustes variolaris (Echinoidea); Oxycomanthus bennetti (Crinoidea); Actinopyga echinites (Holothuroidea); Ctenocystoidea.
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Subkingdom:
Eumetazoa
Clade:
ParaHoxozoa
Clade:
Bilateria
Clade:
Nephrozoa
Superphylum:
Deuterostomia
Clade:
Ambulacraria
Phylum:
Echinodermata Bruguière, 1791 [ex Klein, 1734]
Type genus
Echinus
Linnaeus, 1758
Subphyla and classes[2]
Homalozoa † Gill & Caster, 1960
Cincta †
Soluta †
Stylophora †
Ctenocystoidea † Robison & Sprinkle, 1969
Crinozoa
Crinoidea
Edrioasteroidea †
Cystoidea †
Rhombifera †
Asterozoa
Ophiuroidea
Asteroidea
Echinozoa
Echinoidea
Holothuroidea
Ophiocistioidea †
Helicoplacoidea †
Blastozoa †
Blastoidea †
Cystoidea † von Buch, 1846
Eocrinoidea †Jaekel, 1899
Paracrinoidea † Regnéll, 1945
†=Extinct
An echinoderm (/ɪˈkaɪnəˌdɜːrm,ˈɛkə-/)[3] is any deuterostomal animal of the phylum Echinodermata (/ɪˌkaɪnoʊˈdɜːrmətə/), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies".[4] While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial symmetry (pentamerous symmetry), and are found on the sea bed at every ocean depth from the intertidal zone to the abyssal zone. The phylum contains about 7,600 living species, making it the second-largest group of deuterostomes after the chordates, as well as the largest marine-only phylum. The first definitive echinoderms appeared near the start of the Cambrian.
The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs and limbs; in some cases, they can undergo complete regeneration from a single limb. Geologically, the value of echinoderms is in their ossified dermal endoskeletons, which are major contributors to many limestone formations and can provide valuable clues as to the geological environment. They were the most used species in regenerative research in the 19th and 20th centuries. Further, some scientists hold that the radiation of echinoderms was responsible for the Mesozoic Marine Revolution.
^Smith, A., Zamora, S. & Álvaro, J. The oldest echinoderm faunas from Gondwana show that echinoderm body plan diversification was rapid. Nat Commun 4, 1385 (2013). https://doi.org/10.1038/ncomms2391.
^Stöhr, Sabine (2014). "Echinodermata". WoRMS. World Register of Marine Species. Retrieved 23 February 2014.
An echinoderm (/ɪˈkaɪnəˌdɜːrm, ˈɛkə-/) is any deuterostomal animal of the phylum Echinodermata (/ɪˌkaɪnoʊˈdɜːrmətə/), which includes starfish, brittle...
Clypeaster, common name "cake urchins" or "sea biscuits", is a genus of echinoderms belonging to the family Clypeasteridae. The genus name Clypeaster is...
The echinoderm and flatworm mitochondrial code (translation table 9) is a genetic code used by the mitochondria of certain echinoderm and flatworm species...
a separate phylum. Hemichordates are now thought to be closer to the Echinoderms, and together they form the clade Ambulacraria, the sister phylum of...
shells (e.g. cuttlebones in some cephalopods) or rods (e.g. ossicles in echinoderms), hydrostatically supported body cavities (most), and spicules (sponges)...
Rotula deciesdigitatus is a species of echinoderm in the monotypic genus Rotula, belonging to the family Rotulidae. The species is found in Europe and...
Sea cucumbers are echinoderms from the class Holothuroidea (/ˌhɒləˌθjʊəˈrɔɪdiə, ˌhoʊ-/ HOL-ə-thure-OY-dee-ə, HOHL-). They are marine animals with a leathery...
The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation...
Important animals that live in European seas are zooplankton, molluscs, echinoderms, different crustaceans, squids and octopuses, fish, dolphins and whales...
are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle...
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (/ˌæstəˈrɔɪdiə/). Common usage frequently finds these names being...
The Jurassic (/dʒʊˈræsɪk/ juu-RASS-ik) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years...
Early Cambrian deuterostome which may represent the earliest stem group echinoderm. This species is known from the Ediacaran to Fortunian Yanjiahe Formation...
an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period...
India's Red List of 2018 was released at the Rio+20 Earth Summit. Since then, new animals have been added yearly. While previously this list contained...
of the ancestral echinoderm. It represents the type of basis of all larval forms of, at least, the eleutherozoans (all echinoderms except crinoids),...
bilaterally symmetrical body as adults; the most notable exception is the echinoderms, which extend to pentaradial symmetry as adults, but are only bilaterally...
once a clade of Phylum Echinodermata. It included stalked and sedentary echinoderms. The main class of Pelmatozoa were the Crinoidea which includes sea lily...
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