Ophiuroidea

Plates and hooks of Pectenura excubitor, from Boczarowski (2001). Scale bars = 200 µm.

Belongs within: Eleutherozoa.
Contains: Lysophiurina, Phrynophiurida, Ophiurida, Zeugophiurina, Ophiacanthidae, Hemieuryalidae.

The Ophiuroidea include the brittle stars, a group of starfish-like echinoderms with slender arms distinctly divided from the central disc. In the Ordovician to Devonian Stenurida, the structure of the arm joints more or less allowed for only simple movements, but in other groups the arm plates are progressively modified into articulating vertebrae. Many non-stenurid ophiuroids (except early members of the paraphyletic 'Oegophiurida') also exhibit the movement of the originally lateral madreporite onto the oral surface (Spencer & Wright 1966).

Characters (from Spencer & Wright 1966): Disc usually sharply distinct from slender elongate arms; most primitive forms retaining traces of metapinnular structures in arms, but in most species bulk of arm cavity filled with complex ossicles of axial skeleton; ossicles of adaxial skeleton forming side plates, primitively movable but in advanced forms firmly fixed to axial ossicles. Respiration by means of gills which typically are placed in enlarged interrays. Spines inconspicuous or absent except on lateral edges of arms and jaws.

<==Ophiuroidea [Ophiuromorpha]
    |--Stenurida SW66
    |    |--Klasmuridae [Scalarina] B01
    |    |    |--Klasmura Ruedemann 1916 SW66
    |    |    |    `--*K. mirabilis Ruedemann 1916 SW66
    |    |    `--Pectenura Haude 1982 B01
    |    |         |--*P. horni Haude 1982 B01
    |    |         |--P. excubitor Boczarowski 2001 B01
    |    |         |--P. formosa Boczarowski 2001 B01
    |    |         |--P. hamata Boczarowski 2001 B01
    |    |         |--P. pecten Boczarowski 2001 B01
    |    |         `--P. senta Boczarowski 2001 B01
    |    |--Parophiurina [Parophiura] B01
    |    |    |--Eophiura Jaekel 1903 [Eophiuridae] SW66
    |    |    |    `--E. bohemica Schuchert 1914 SW66
    |    |    |--Stenaster Billings 1858 [incl. Tetraster Nicholson & Etheridge 1880; Stenasteridae] SW66
    |    |    |    `--S. obtusus (Forbes 1848) [=Uranaster obtusus; incl. *S. salteri Billings 1858] SW66
    |    |    `--Palaeuridae B01
    |    |         |--Palaeura Jaekel 1903 B01
    |    |         |    `--*P. neglecta Jaekel 1903 SW66
    |    |         |--Medusaster Stürtz 1890 SW66
    |    |         |    `--*M. rhenanus Stürtz 1890 SW66
    |    |         `--Umerophiura Boczarowski 2001 B01
    |    |              |--*U. opiparia Boczarowski 2001 B01
    |    |              `--U. umera Boczarowski 2001 B01
    |    `--Proturina B01
    |         |--Phragmactis Spencer 1940 [Phragmactidae, Phragmactinidae] SW66
    |         |    `--*P. grayae Spencer 1940 SW66
    |         |--Bdellacoma Salter 1857 [Bdellacomidae] SW66
    |         |    `--*B. vermiformis (Salter 1857) [=Palaeocoma (*Bdellacoma) vermiformis] SW66
    |         |--Rhopalocomidae SW66
    |         |    |--Rhopalocoma Salter 1857 SW66
    |         |    |    `--*R. pyrotechnica (Salter 1857) [=Palaeocoma (*Rhopalocoma) pyrotechnica] SW66
    |         |    `--Ptilonaster Hall 1868 SW66
    |         |         `--*P. princeps Hall 1868 SW66
    |         `--Pradesuridae B01
    |              |--Pradesura Spencer 1951 SW66
    |              |    `--*P. jacobi (Thoral 1935) [=Palaeura jacobi] SW66
    |              `--Stuertzaster Etheridge 1899 (see below for synonymy) SW66
    |                   |--*S. marstoni (Salter 1857) [=*Palaeocoma marstoni] SW66
    |                   |--S. colvini SW66
    |                   |--S. liquidus Boczarowski 2001 B01
    |                   |--S. spinosissimus SW66
    |                   `--S. utroquecognitus Boczarowski 2001 B01
    `--Oegophiurida [Oegophiuroidea] SW66
         |--Lysophiurina SW66
         `--+--+--Phrynophiurida S97
            |  `--Ophiurida S97
            `--+--Zeugophiurina S97
               `--Laemophiurina [Laemophiurida] SW66
                    |--Ophiacanthidae S97
                    `--Hemieuryalidae SW66

Ophiuroidea incertae sedis:
  Calyptactis Spencer 1930 B02, SW66 [Calyptactinidae]
    `--*C. spinosus Spencer 1930 B02
  ‘Asteriacites’ ophiurus von Schlotheim 1820 (n. d.) (see below for synonymy) WR78
  Strataster Kesling & Le Vasseur 1971 B01
  Acroura Agassiz 1836 (n. d.) SW66
    `--*A. prisca (Münster in Goldfuss 1831) (n. d.) [=Ophiura prisca] SW66
  Ataxaster Jaekel 1903 (n. d.) SW66
    `--*A. pygmaeus Jaekel 1903 (n. d.) SW66
  Ephippiellum Lomnicki 1899 (n. d.) SW66
    `--*E. symmetricum Lomnicki 1899 (n. d.) SW66
  Dolicharthra Berry 1938 SW66
    `--*D. bemelenica Berry 1938 SW66
  Ophiaxina Müller 1950 SW66
    `--*O. intercarinata Müller 1950 SW66
  Ophioma Pomel 1887 (n. d.) SW66
    `--*O. juliensis Pomel 1887 (n. d.) SW66
  Ophiotrigonum Hess 1960 SW66
    `--*O. oxfordiense Hess 1960 SW66
  Ophiurella Agassiz 1836 (n. d.) SW66
    `--*O. speciosa (Münster in Goldfuss 1831) [=Ophiura speciosa] SW66
  Ophiuriocoma Valette 1929 SW66
    `--*O. mazenoti Valette 1929 SW66
  Platyarthra Berry 1938 SW66
    `--*P. jekerica Berry 1938 SW66
  Pseudaspidura Kolosváry 1941 (n. d.) SW66
    `--*P. hungarica Kolosváry 1941 (n. d.) SW66
  Schizospondylus Müller 1950 SW66
    `--*S. jasmundiana Müller 1950 SW66
  Transspondylus Müller 1950 (n. d.) SW66
    `--*T. bubnoffi Müller 1950 (n. d.) SW66
  Xenura Schöndorf 1938 (n. d.) SW66
    `--*X. kobuldi Schöndorf 1938 (n. d.) SW66

‘Asteriacites’ ophiurus von Schlotheim 1820 (n. d.) [incl. Asteriatites eremita von Schlotheim 1813 (n. n.)] WR78

Stuertzaster Etheridge 1899 [=Palaeocoma Salter 1857 non d’Orbigny 1850; incl. Erinaceaster Lehmann 1957] SW66

*Type species of generic name indicated

REFERENCES

[B02] Blake, D. B. 2002. Compsaster formosus Worthen & Miller (Asteroidea; Echinodermata): a Carboniferous homeomorph of the post-Paleozoic Asteriidae. Paläontologische Zeitschrift 76 (2): 357–367.

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

[S97] Smith, A. B. 1997. Echinoderm larvae and phylogeny. Annual Review of Ecology and Systematics 28: 219–241.

[SW66] Spencer, W. K., & C. W. Wright. 1966. Asterozoans. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U4–U107. The Geological Society of America, Inc., and The University of Kansas Press.

[WR78] Wienberg Rasmussen, H. 1978. Articulata. In: Moore, R. C., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt T. Echinodermata 2. Crinoidea vol. 3 pp. T813–T927. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).