Echinoidea

Melonechinus multiporus, from here.

Belongs within: Eleutherozoa.
Contains: Echinocystitoida, Cidaroida, Euechinoidea.

The Echinoidea include the sea urchins, free-living echinoderms with an ancestrally subspherical test bearing mobile appendages (including spines). The ancestral echinoid morphology includes a ventral masticatory apparatus, the lantern, though this has been lost in some subgroups. The anus is ancestrally dorsal, opposite the ventral mouth, with the madreporite close by. Echinoids have been divided into two subclasses based on the ancestral presence (Euechinoidea) or absence (Perischoechinoidea) of external gills, but the latter are almost certainly paraphyletic to the former.

Other than the Cidaroida, 'perischoechinoids' are restricted to the Palaeozoic. The Ordovician Bothriocidaris may represent the sister taxon of other echinoids, and is characterised by a rigid test with a single interambulacral column that does not reach the margin of the peristome, and without differentiated genital plates (Kier 1966). The Palaechinoida, known from the Silurian to the Permian, have plates that are not strongly imbricate, with the ambulacral plates bevelling over the interambulacra. They are divided between the Cravenechinidae, with small perforate or imperforate primary tubercles, and the Lower Carboniferous Palaechinidae in which the tubercles are always imperforate (Kier 1966).

Characters (from Ubaghs 1978): Free-living quinqueradiate echinoderms with plated test, bearing movable appendages (spines, pedicellariae, spheridia) externally; mouth directed toward substrate, primarily with, secondarily without masticatory apparatus; 2 principal systems of plates, 1) an apical system invariably including 5 ocular plates and 5 or fewer genital plates; 2) a coronal system composed of 5 ambulacral and 5 interambulacral areas, each one composed of 1, 2, or more meridional columns; ambulacral plates perforated for passage of tube feet.

<==Echinoidea (see below for synonymy)
    |--Bothriocidaris Eichwald 1859 K66 [Bothriocidaridae, Bothriocidaroida D66]
    |    `--*B. globulus Eichwald 1859 K66
    `--+--+--Echinocystitoida D66
       |  `--+--Cidaroida D66
       |     `--Euechinoidea D66
       `--Palaechinoida D66
            |  i. s.: Wrighthia Pomel 1869 [=Wrightella Pomel 1883] K66
            |           `--*W. phillipsiae (Forbes 1848) [=Palechinus phillipsiae, *Wrightella phillipsiae] K66
            |         Xysteria Pomel 1883 K66
            |           `--*X. konigii (M’Coy 1844) [=Palaechinus konigii] K66
            |--Cravenechinidae K66
            |    |--Cravenechinus Hawkins 1946 K66
            |    |    `--*C. uniserialis Hawkins 1946 K66
            |    |--Gotlandechinus Regnéll 1956 K66
            |    |    `--*G. balticus Regnéll 1956 K66
            |    `--Xenechinus Kier 1958 K66
            |         `--*X. parvus Kier 1958 K66
            `--Palaechinidae [Palaeechinidae] K66
                 |--Oligoporus Meek & Worthen 1862 [=Melonopsis Meek & Worthen 1866] K66
                 |    `--*O. danae (Meek & Worthen 1861) [=Melonites danae, *Melonopsis danae] K66
                 |--Palaechinus M’Coy 1844 (see below for synonymy) K66
                 |    |--*P. ellipticus M’Coy 1844 K66
                 |    `--P. canadensis K66
                 |--Lovenechinus Jackson 1912 (nom. cons.) [incl. Eriechinus Pomel 1883, Typhlechinus Neumayr 1889] K66
                 |    |--*L. missouriensis (Jackson 1896) [=Oligoporus missouriensis] K66
                 |    `--‘Palaechinus’ sphaericus M’Coy 1844 [=*Eriechinus sphaericus, *Typhlechinus sphaericus] K66
                 |--Maccoya Pomel 1869 K66
                 |    |--*M. gigas (M’Coy 1844) [=Palaechinus gigas] K66
                 |    `--M. sphaerica K66
                 `--Melonechinus Meek & Worthen 1861 (see below for synonymy) K66
                      |--*M. multiporus (Owen & Norwood 1846) [=*Melonites multipora, *Melechinus multiporus] K66
                      `--‘*Donbassechinus’ kumpani Faas 1941 K66

Echinoidea incertae sedis:
  Acanthotrema B01
  ‘Reophax’ lodderae Goddard & Jensen 1907 Q72
  Cavanechinus warreni Brown 1967 F71
  Besairecidaris Lambert 1936 FP66
    `--*B. ankarensis Lambert 1936 FP66
  Bramus de Gregorio 1930 FP66
    `--*B. simplex de Gregorio 1930 FP66
  Crinocidaris de Gregorio 1930 FP66
    `--*C. unicus de Gregorio 1930 FP66
  Dallonia Lambert in Dalloni 1920 FP66
    `--*D. squamosa Lambert in Dalloni 1920 FP66
  Firmacidaris Lambert 1937 FP66
    `--*F. precincta (Lambert 1933) [=Sphaerotiaris precincta] FP66
  Gajechinus Lambert & Thiéry 1914 FP66
    `--*G. subcrenatus (Duncan & Sladen 1885) [=Echinus subcrenatus] FP66
  Ombria Quenstedt 1873 FP66
  Pleurechinus Agassiz 1841 FP66
    `--*P. bothryoides Agassiz 1841 [=Cidaris bothryoides Klein 1754 (pre-Linnean)] FP66
  ‘Protocidaris’ de Gregorio 1930 non Whidborne 1898 FP66
    `--*P. bencontestus de Gregorio 1930 FP66
  Radiolus FP66
  Rhabdechinus Lambert 1910 FP66
    `--*R. belone [=Cidaris belone] FP66
  Vernius de Gregorio 1930 FP66
    `--*V. elaboratus de Gregorio 1930 FP66
  Cataproctus Lambert 1931 (n. d.) A66
  Coenocentrotus Clark 1912 (n. d.) A66
  Diegocorys Lambert & Thiéry 1925 (n. d.) A66
  ‘Echinobrissus’ Breynius in Pomel 1883 (n. d.) non Gray 1825 A66
  Insuflaster Borchard in d’Orbigny 1854 (n. d.) [=Insufulaster (l. c.)] A66
  Nucleolus von Martens 1866 (n. d.) [incl. Mecostobrissus Lambert 1912] A66
  Mengaudia Lambert 1917 (n. d.) A66
  Oligopodia Duncan 1889 (n. d.) A66
  Proechinus Cuénot 1891 A66
  ‘Spatangus’ Leske 1778 (nom. rej.) non Gray 1825 [=Spatangites Leske 1778] A66
  Tingitanaster Lambert & Thiéry 1925 (n. d.) A66
  Neobothriocidaris EL11
  Stoliczkiella Carter 1888 LT64
    `--*S. theobaldi Carter 1888 LT64
  Plesioderma indicum WP99

Echinoidea [Adostella, Cirrhispinigrada, Cycloides, Echinata, Echini, Echinida, Echinidea, Echinides, Echinodea, Echinomorpha, Echinus, Pedicellata, Perischoechinida, Perischoechinoidea]

Melonechinus Meek & Worthen 1861 [=Melechinus Quenstedt 1875, Melonites Norwood & Owen 1846 non Lamarck 1812; incl. Donbassechinus Faas 1941] K66

Palaechinus M’Coy 1844 [=Palaeechinus Lovén 1874, Palechinus Scouler in Griffith 1840 (n. n.), Palechtinus (l. c.)] K66

*Type species of generic name indicated

REFERENCES

[A66] Anon. 1966. Doubtful nominal genera of echinoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U633. The Geological Society of America, Inc., and The University of Kansas Press.

[B01] Boczarowski, A. 2001. Isolated sclerites of Devonian non-pelmatozoan echinoderms. Palaeontologia Polonica 59: 1–219.

[D66] Durham, J. W. 1966. Echinoids—classification. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U270–U295. The Geological Society of America, Inc., and The University of Kansas Press.

[EL11] Erwin, D. H., M. Laflamme, S. M. Tweedt, E. A. Sperling, D. Pisani & K. J. Peterson. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334: 1091–1097.

[FP66] Fell, H. B., & D. L. Pawson. 1966. Echinacea. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U367–U440. The Geological Society of America, Inc., and The University of Kansas Press.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[K66] Kier, P. M. 1966. Noncidaroid Paleozoic echinoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U298–U312. The Geological Society of America, Inc., and The University of Kansas Press.

[LT64] Loeblich, A. R., Jr & H. Tappan. 1964. Sarcodina: chiefly “thecamoebians” and Foraminiferida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt C. Protista 2 vol. 2. The Geological Society of America and The University of Kansas Press.

[Q72] Quilty, P. G. 1972. The biostratigraphy of the Tasmanian marine Tertiary. Papers and Proceedings of the Royal Society of Tasmania 106: 25–44.

Ubaghs, G. 1978. Classification of the echinoderms. In Treatise on Invertebrate Paleontology pt. T. Echinodermata 2. Crinoidea (R. C. Moore & C. Teichert, eds) vol. 1 p. T359-T367. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[WP99] Walter, D. E., & H. C. Proctor. 1999. Mites: Ecology, Evolution and Behaviour. CABI Publishing: Wallingford (UK).