Atelostomata

Aboral view of Late Palaeocene Togocyamus seefriedi, from here.

Belongs within: Euechinoidea.
Contains: Holectypoida, Clypeasteroida, Cassiduloida, Holasteroida, Asterostomatidae, Toxasteridae, Hemiasterina, Micrasterina.

The Atelostomata is recognised as one of the major groups of irregular echinoids, in which the ancestral pentaradial symmetry has been altered towards a bilateral symmetry with the anus moved towards or onto the adoral surface. Many live buried in sand or muddy substrates. In members of the Atelostomat, the lantern is absent in adults and food is obtained by gathering organic particles contained in the sediment (by gathering with the tube feet and/or ingesting the sediment directly). In the other recognised grouping of irregular echinoids, the Gnathostomata, the lantern and jaws are retained. Major subgroups of irregular echinoids include the Spatangoida, the heart urchins, which are adapted for living in (often relatively deep) burrows and have the periproct located towards the posterior end of the test (Fischer 1966).

Characters (from Durham 1966): Corona rigid; periproct outside apical system; no compound ambulacral plates; lantern, girdle, and branchial slits absent in adult; apical system and peristome rarely opposite; primary tubercles usually perforate and crenulate; primary spines hollow; interambulacra invariably wider than ambulacra on oral surface.

Atelostomata
    |--+--Gnathostomata U78
    |  |    |--Holectypoida U78
    |  |    `--+--Clypeasteroida B01
    |  |       `--Togocyamus Oppenheim 1915 M89
    |  |            `--*T. seefriedi (Oppenheim 1915) [=Echinocyamus (*Togocyamus) seefriedi] M89
    |  `--+--Cassiduloida B01
    |     `--Neolampadidae [Neolampadina, Neolampadoida] D66
    |          |--Neolampas Agassiz 1869 DW66
    |          |    `--*N. rostellata Agassiz 1869 DW66
    |          |--Tropholampas Clark 1923 DW66
    |          |    `--*T. loveni (Studer 1880) [=Catopygus loveni] DW66
    |          |--Anochanus Grube 1868 DW66
    |          |    `--*A. sinensis Grube 1868 DW66
    |          |--Aphanophora de Meijere 1902 DW66
    |          |    `--*A. echinobrissoides de Meijere 1902 DW66
    |          |--Nannolampas Mortensen 1948 DW66
    |          |    `--*N. tenera (de Meijere 1902) [=Neolampas tenera] DW66
    |          |--Notolampas Philip 1963 DW66
    |          |    `--*N. flosculus Philip 1963 DW66
    |          `--Pisolampas Philip 1963 DW66
    |               `--*P. concinna Philip 1963 DW66
    `--+--Holasteroida F66
       `--Spatangoida [Amphisternata] U78
            |  i. s.: Barnumia Cooke 1953 F66
            |           `--*B. browni Cooke 1953 F66
            |         Cestobrissus Lambert 1912 F66
            |           `--*C. lorioli Lambert 1912 F66
            |         Cottreaucorys Lambert 1920 F66
            |           `--*C. blayaci (Cotteau 1909) [=Homoeaster blayaci] F66
            |         Enichaster de Loriol 1882 F66
            |           `--*E. oblongus de Loriol 1882 F66
            |         Gonzalezaster Sánchez Roig 1952 F66
            |           `--*G. lamberti (Sánchez Roig 1949) [=Nudobrissus lamberti] F66
            |         Homoeopetalus Arnold & Clark 1934 F66
            |           `--*H. axiologus Arnold & Clark 1934 F66
            |         Mazzettia Lambert & Thiéry 1915 [=Manzonia Pomel 1883 non Brusina 1870] F66
            |           `--*M. pareti (Manzoni 1878) [=Maretia pareti, *Manzonia pareti] F66
            |         Niponaster Lambert 1920 F66
            |           `--*N. hokkaidensis Lambert 1920 F66
            |         Nudobrissus Lambert 1920 [=Dictyaster Stefanini 1908 non Wood-Mason & Alcock 1891] F66
            |           `--*N. malatinus (Mazzetti 1885) [=Pericosmus malatinus, *Dictyaster malatinus] F66
            |         Pusillaster Lambert 1920 F66
            |           `--*P. dallonii Lambert 1920 F66
            |         Royasendia Airaghi 1901 F66
            |           `--*R. canavarii Airaghi 1901 F66
            |         Amygdala Gray 1825 (n. d.) A66
            |         Brissoides Leske 1778 (n. d.) A66
            |         Cardiopatagus Pomel 1883 (n. d.) A66
            |         ‘Cassis’ Parkinson 1811 (n. d.) non Scopoli 1777 A66
            |         Neopatagus Sánchez-Roig 1953 (n. d.) A66
            |         Pleraster Quenstedt 1874 (n. d.) A66
            |--Asterostomatidae F66
            |--Toxasteridae F66
            |--Hemiasterina F66
            `--Micrasterina F66

Atelostomata incertae sedis:
  Desorella Cotteau 1855 (see below for synonymy) WD66
    |--*D. elata (Desor 1847) [=Hyboclypus elatus, *Desoria elata] WD66
    `--‘Dysaster’ semiglobosus Desory 1842 [=*Pachyclypus semiglobosus] WD66
  Galeroclypeus Cotteau 1873 WD66
    `--*G. peroni Cotteau 1873 WD66
  Infraclypeus Gauthier 1875 WD66
    `--*I. thalebensis Gauthier 1875 WD66
  Loriolella Fucini 1904 [incl. Pseudopygaster Hawkins 1922] WD66
    |--*L. ludovici (Meneghini 1867) [=Cidaris ludovici] WD66
    `--L. eos (Hawkins 1922) [=*Pseudopygaster eos] WD66
  Menopygus Pomel 1883 [incl. Pyrinodia Pomel 1883, Pyrenodia (l. c.)] WD66
    |--*M. nodoti (Cotteau 1859) [=Galeropygus nodoti] WD66
    `--‘Desorella’ guerangeri Cotteau 1862 [=*Pyrinodia guerangeri] WD66

Desorella Cotteau 1855 [=Desoria Cotteau 1855 nec Nicolet 1842 nec Gray 1851; incl. Pachyclypus Desor 1858, Pachyclypeus (l. c.)] WD66

*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.

[DW66] Duncan, J. W., & C. D. Wagner. 1966. Neolampadoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U628–U630. The Geological Society of America, Inc., and The University of Kansas Press.

[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.

[F66] Fischer, A. G. 1966. Spatangoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U543–U628. The Geological Society of America, Inc., and The University of Kansas Press.

[M89] Mooi, R. 1989. Living and fossil genera of the Clypeasteroida (Echinoidea: Echinodermata): an illustrated key and annotated checklist. Smithsonian Contributions to Zoology 488: 1–51.

[U78] Ubaghs, G. 1978. Classification of the echinoderms. In: Moore, R. C., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt T. Echinodermata 2. Crinoidea vol. 1 p. T359–T367. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[WD66] Wagner, C. D., & J. W. Durham. 1966. Gnathostomata or Atelostomata. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U631–U632. The Geological Society of America, Inc., and The University of Kansas Press.