HIERARCHICAL CLASSIFICATION OF THE PHYLUM ECHINODERMATA
| EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>ECHINODERMATA |
PHYLUM ECHINODERMATA LINKS
| The following taxonomic system is based on Wray (1999), Pechenik (2005), and Tudge (2000) for its organization into subphyla and the default recognition of the Class Concentricycloidea (“sea daisies”) as a separate class. The organization of the classes comes from Brusca and Brusca (2003). |
- SUBPHYLUM PELMATOZOA
- This includes the crinoids, blastoids and cystoids. Only the crinoids have surviving taxa.
- CLASS CRINOIDEA (5 ORDERS)
- Attached to substrate for some or all of their life by a stalk; cup-like body contained within calyx; mouth directed upwards; surrounded by 5 moveable arms which may repeatedly fork; arms with ciliated grooves; numerous side pinnules; finger-shaped tube feet; without madreporite; anus on oral surface; body and arms with heavily calcified, abutting plates and with small tissue volume; separate sexes; gonads on pinnules; eggs brooded or form vitellaria larvae; filter feeders.
- Antedon, Asterometra, Cenocrinus, Comantheria, Comanthina, Isometra, Metacrinus, Neometra, Phixometra, Zygometra.
- Attached to substrate for some or all of their life by a stalk; cup-like body contained within calyx; mouth directed upwards; surrounded by 5 moveable arms which may repeatedly fork; arms with ciliated grooves; numerous side pinnules; finger-shaped tube feet; without madreporite; anus on oral surface; body and arms with heavily calcified, abutting plates and with small tissue volume; separate sexes; gonads on pinnules; eggs brooded or form vitellaria larvae; filter feeders.
- SUBPHYLUM ELEUTHEROZOA
- CLASS ASTEROIDEA (7 ORDERS)
- Star-shaped or pentagonal; 5 or more arms merged gradually to central disk; endoskeleton flexible; ampullae (internal bulbous swelling associated with the external tube foot) single-lobed, bilobed in one species; short spines and pedicellariae.
- Platysterias.
- Astropecten, Caymanostella, Ctenodiscus, Lethmaster.
- Amphiaster, Archaster, Asterodon, Chaetaster, Hoplaster, Linckia, Odonaster, Oreaster.
- Acanthaster, Echinaster, Henricia, Pteraster, Remaster, Solaster.
- Asterias, Brisinga, Evasterias, Heliaster, Leptasterias, Pisaster, Pycnopodia, Styasterias.
- Luidia, Dermasterias, Patiria, Echinaster, Pteraster, Asterina,
- Star-shaped or pentagonal; 5 or more arms merged gradually to central disk; endoskeleton flexible; ampullae (internal bulbous swelling associated with the external tube foot) single-lobed, bilobed in one species; short spines and pedicellariae.
- CLASS ASTEROIDEA (7 ORDERS)
- SUPERCLASS CRYPTOSYRINGIDA
- CLASS CONCENTRICYLOIDEA (1 ORDER?)
- Small (<1mm), discoid, dorsoventrally flattened, marginal spines, but no arms; gut very reduced; “sea daisies”.
- Xyloplax.
- Small (<1mm), discoid, dorsoventrally flattened, marginal spines, but no arms; gut very reduced; “sea daisies”.
- CLASS OPHIUROIDEA (3 ORDERS)
- Five slender arms, sharply set off from central disk; no suckers or pedicellariae.
- Ophiocanops.
- Asteronyx, Astrodia, Gorgonocephalus, Ophiomyxa.
- Amphiophiura, Ophiactis, Ophiocoma, Ophioderma, Ophiolepis, Ophiomusium, Ophionereis, Ophiopholis, Ophiothrix, Ophiura.
- Five slender arms, sharply set off from central disk; no suckers or pedicellariae.
- CLASS ECHINOIDEA (15 ORDERS DISTRIBUTED IN 2 SUBCLASSES)
- Body globular, heart or disk-shaped; endoskeleton usually rigid test of closely fitted plates; covered with moveable spines; 3-jawed pedicellariae.
- SUBCLASS CIDAROIDEA
- Cidaris, Eucidaris, Notocidaris, Phyllacanthus, Psychocidaris.
- SUBCLASS EUECHINOIDEA
- Araeosoma, Asthenosoma, Phormosoma, Sperosoma.
- Astropyga, Aspidodiadema, Caenopedina, Diadema, Micropyga, Plesiodiadema.
- Arbacia, Echinometra, Echinus, Heterocentrotus, Lytechinus, Paracentrotus, Salenia, Strongylocentrotus, Toxopneustes, Tripneustes.
- Cassidulus, Clypeaster, Dendraster, Echinocardium, Echinodiscus, Echinolampus, Encope, Fibularia, Hemiaster, Lovenia, Maretia, Mellita, Meoma, Metalia, Micropetalon, Spatanga, Urechinus.
- Apatopygus, Claveriosoma, Diadema, Echinarachinus, Echinoneus, Moira.
- SUBCLASS CIDAROIDEA
- Body globular, heart or disk-shaped; endoskeleton usually rigid test of closely fitted plates; covered with moveable spines; 3-jawed pedicellariae.
- CLASS HOLOTHUROIDEA (6 ORDERS DISTRIBUTED IN 3 SUBCLASSES)
- Body elongate in oral-aboral axis; body wall thin to leathery; endoskeleton of microscopic ossicles embedded in body wall; no arms, spines or pedicellariae.
- SUBCLASS DENDROCHIROTACEA
- Echinocucumis, Holothuria, Mitsukuriella, Rhopalodina, Sphaerothuria, Vaneyella, Ypsilothuria.
- Cucumaria, Eupentacta, Paracucumis, Peniagone, Placothuria, Psolus, Thyone, Thyonepsolus.
- SUBCLASS ASPIDOCHIROTACEA
- Actinopyga, Astichopus, Bathyplotes, Holothuria, Isostichopus, Parastichopus, Stichopus.
- Benthodytes, Deima, Enypniastes, Pelagothuria, Scotoplanes.
- SUBCLASS APODACEA
- Caudina, Molpadia, Trochoderma.
- Euapta, Leptosynapta, Synapta.
- SUBCLASS DENDROCHIROTACEA
- Body elongate in oral-aboral axis; body wall thin to leathery; endoskeleton of microscopic ossicles embedded in body wall; no arms, spines or pedicellariae.
- CLASS CONCENTRICYLOIDEA (1 ORDER?)
| LITERATURE CITED Barnes, R. D. 1980. Invertebrate Zoology. Saunders College/Holt, Rinehart and Wilson, Philadelphia. Barnes. R. S. K. 1984a. Kingdom Animalia. IN: R. S. K. Barnes, ed. A Synoptic Classification of Living Organisms. Sinauer Associates, Inc., Sunderland, MA. pp. 129-257. Brusca, R. C. and G. J Brusca. 2003. Invertebrates. Sinauer Associates, Inc. Sunderland, Mass. Buchsbaum, R. 1938. Animals Without Backbones, An Introduction to the Invertebrates. The University of Chicago Press. Chicago. Colbert, E. H. and M. Morales. 1991. Evolution of the Vertebrates, A History of the Backboned Animals Through Time. WILEY-LISS, Inc. New York. Delsuc, F., H. Brinkmann, D. Chourrout, and H. Philippe. 2006. Tunicates and not cephalochordates are the closest living relatives of vertebrates. Nature. 439: 965-968. Hickman, C. P. 1973. Biology of the Invertebrates. The C. V. Mosby Company. Saint Louis. Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Company. New York. Nielsen, C. 2001. Animal Evolution: Interrelationships of the Living Phyla. 2nd Edition. Oxford University Press. Oxford. Pechenik, J. A. 2005. Biology of the Invertebrates. McGraw-Hill. New York. Putnam, N. H., T. Butts, D. E. K. Ferrier, R. F. Furlong, U. Hellsten, T. Kawashima, M. Robinson-Rechavi, E. Shoguchi, A. Terry, J.-K. Yu, E. Benito-Gutiérrez, I. Dubchak, J. Garcia-Fernà ndez, J. J. Gibson-Brown, I. V. Grigoriev, A. C. Horton, P. J. de Jong, J. Jurka, V. V. Kapitonov, Y. Kohara, Y. Kuroki, E. Lindquist, S. Lucas, K. Osoegawa, L. A. Pennacchio, A. A. Salamov, Y. Satou, T. Sauka-Spengler, J. Schmutz, T. Shin-I, A. Toyoda, M. Bronner-Fraser, A. Fujiyama, L. Z. Holland, P. W. H. Holland, N. Satoh, and D. S. Rokhsar. 2008. The amphioxus genome and the evolution of the chordate karyotype. Nature. 453: 1064-1071. Ruppert, E. E., R. S. Fox, and R. D. Barnes. 2004. Invertebrate Zoology: A Functional Evolutionary Approach. Seventh Edition. Thomson, Brooks/Cole. New York. pp. 1-963. Storer, T. I. and R. L. Usinger. 1965. General Zoology. 4th Edition. McGraw-Hill Book Company. New York. Tudge, C. 2000. The Variety of Life, A Survey and a Celebration of all the Creatures That Have Ever Lived. Oxford University Press. New York. Wray, G.A. 1999. Echinodermata, Spiny-skinned animals: sea urchins, starfish, and their allies. In: Tree of Life Web Project. http://tolweb.org/Echinodermata. Accessed 22 January 2010. |
| By Jack R. Holt and Carlos A. Iudica. Last revised: 01/25/2010 |
