Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-26T03:55:16.541Z Has data issue: false hasContentIssue false

The class Somasteroidea (Echinodermata, Asterozoa): morphology and occurrence

Published online by Cambridge University Press:  01 October 2015

Daniel B. Blake
Affiliation:
Department of Geology, University of Illinois, 506 W. Springfield, Champaign, IL 61820, USA 〈dblake@illinois.edu〉
Thomas E. Guensburg
Affiliation:
Sciences Division, Rock Valley College, 3301 N. Mulford Road, Rockford IL, 61114 USA 〈t.guensburg@rockvalleycollege.edu〉

Abstract

The class Somasteroidea Spencer, 1951, is basal within the subphylum Asterozoa. Members are most readily recognized by presence of series of rod-like so-called virgal ossicles extending laterally from each ambulacral ossicle. Five somasteroid genera are recognized and assigned to two families. Four genera are Gondwanan, three of these (Chinianaster, Thoralaster, Villebrunaster) from the Lower Ordovician Tremadocian of France and one (Archegonaster) from the Middle Ordovician upper Darriwilian of the Czech Republic. The fifth genus, Ophioxenikos, is Laurentian from the Floian of Nevada. Catervaparmaster, previously assigned to the Somasteroidea, is left in open nomenclature; absence of virgal-series ossicles favors a lineage apart from the principal asterozoan clades. Asterozoan fossils are readily separated from fossils of other echinoderm groups. The subphylum therefore is thought to be monophyletic, its ancestry unknown. Skeletonized representatives of the four major asterozoan clades first occur through a relatively narrow Early Ordovician stratigraphic interval. Robust skeletons therefore are thought to have evolved after a time of unknown duration including only lineages that were no more than weakly calcified. The French occurrences are from a relatively deep distal shelf setting on soft substrates whereas the Nevada occurrence was in a shallower, active setting. Differences document early ecologic diversification.

Type
Articles
Copyright
Copyright © 2015, The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bergström, S.M., Chen, X., Gutiérez-Marco, J.C., and Dronov, A., 2008, The new chronostratigraphic classification of the Ordovician System and its relations to major regional series and stages and to δ13C chemostratigraphy: Lethaia, v. 42, p. 97107. DOI 10.1111/j.1502–3931.2008.00136.xCrossRefGoogle Scholar
Billings, E., 1858, On the Asteridae of the Lower Silurian rocks of Canada. Figures and descriptions of Canadian organic remains: Geological Survey of Canada, Decade 3, p. 7585.Google Scholar
Blake, D.B., 1982, Somasteroidea, Asteroidea, and the affinities of Luidia (Platasterias) latiradiata: Palaeontology, v. 25, p. 167191.Google Scholar
Blake, D.B., 2000, An Archegonaster-like somasteroid (Echinodermata) from Pomeroy, Co. Tyrone, Northern Ireland: Irish Journal of Earth Sciences, v. 18, p. 8999.Google Scholar
Blake, D.B., 2008, A new Ordovician asteroid (Echinodermata) with somasteroid-like skeletal elements: Journal of Paleontology, v. 82, p. 645656.CrossRefGoogle Scholar
Blake, D.B., 2013, Early Asterozoan (Echinodermata) diversification: a paleontologic quandary: Journal of Paleontology, v. 87, p. 353372.CrossRefGoogle Scholar
Blake, D.B., 2014, Two Ordovician asterozoans of problematic affinities: Journal of Paleontology, v. 88, p. 11631173.CrossRefGoogle Scholar
Blake, D.B., and Guensburg, T.E., 1993, New Lower and Middle Ordovician stelleroids (Echinodermata) and their bearing on the origins and early history of the stelleroid echinoderms: Journal of Paleontology, v. 67, p. 103113.CrossRefGoogle Scholar
Blake, D.B., Guensburg, T.E., Sprinkle, J., and Sumrall, C., 2007, A new phylogenetically significant Lower Ordovician asteroid (Echinodermata): Journal of Paleontology, v. 81, p. 12571265.CrossRefGoogle Scholar
Byrd, W.J., 1970, Geology of the Ely Springs Range, Lincoln County, Nevada: unpublished MS thesis, University of Illinois at Urbana-Champaign, 41 p.Google Scholar
Byrd, W.J., 1970, Geology of the Ely Springs Range, Lincoln County, Nevada: Wyoming Geological Association Earth Science Bulletin, v. 3, p. 2332.Google Scholar
Caso, M.E., 1945, Modificacion de la familia Luidiidae Verrill. Las subfamilias nuevas de la familia Luidiidae y observaciores acerca de Platasterias latiradiata: Anales del Instituto de Biología, v. 16, p. 459473.Google Scholar
Church, S.B., 1974, Lower Ordovician patch reefs in western Utah: Brigham Young University Geology Studies, v. 21, p. 4162.Google Scholar
Datillo, B., 1993, The Lower Ordovician Fillmore Formation of Western Utah: storm-dominated sedimentation on a passive margin: Brigham Young University Geology Studies, v. 39, p. 71100.Google Scholar
Dean, J., 1999, What makes an ophiuroid? A morphological study of the problematic Ordovician stelleroid Stenaster and the palaeobiology of the earliest asteroids and ophiuroids: Zoological Journal of the Linnean Society, v. 126, p. 225250.CrossRefGoogle Scholar
Ethington, R., 2008, Conodonts from the Margie Limestone in the Highland Border Complex, River North Esk: Scottish Journal of Geology, v. 44, p. 7581.CrossRefGoogle Scholar
Fell, H.B., 1963a, The phylogeny of sea-stars: Philosophical Transactions of the Royal Society B, v. 246, p. 381435.Google Scholar
Fell, H.B., 1963b, A new family and genus of Somasteroidea: Transactions of the Royal Society of New Zealand: Zoology, v. 3, p. 143146.Google Scholar
Ferguson, J.C., 1988, Madreporite and anus function in fluid volume regulation of a starfish (Echinaster graminicola), in Burke, R.D., Mladenov, P.V., Lambert, P., and Parsley, R.L., eds., Echinoderm biology, Proceedings of the Sixth International Echinoderm Conference, Victoria, Canada: Rotterdam, A.A. Balkema, p. 603–609.Google Scholar
Ferguson, J.C., 1990, Hyperosmotic properties of the fluids of the perivisceral coelom and water vascular system of starfish kept under stable conditions: Comparative Biochemistry and Physiology, v. 95A, p. 245248.CrossRefGoogle Scholar
Ferguson, J.C., 1992, The function of the madreporite in body fluid volume maintenance by an intertidal starfish, Pisaster ochraceus: Biological Bulletin, v. 183, p. 482489.CrossRefGoogle ScholarPubMed
Ferguson, J.C., 1994, Madreporite inflow of seawater to maintain body fluids in five species of starfish, in David, B., Guille, A., Feral, J.-P., and Roux, M., eds., Echinoderms through time, Proceedings of the Eighth International Echinoderm Conference, Dijon, France: Rotterdam, A.A. Balkema, p. 285–289.CrossRefGoogle Scholar
Ferguson, J.C., 1995, The structure and mode of function of the water vascular system of a brittlestar, Ophioderma appressum: Biological Bulletin, v. 188, p. 98110.CrossRefGoogle ScholarPubMed
Forbes, E., 1849, Protaster sedgwickii, Memoirs of the Geological Survey of the United Kingdom, Figures and Descriptions iIlustrative of British Organic Remains: Decade 1, pl. 4, figs. 1–4.Google Scholar
Haeckel, E.H., 1866, Generelle morphologie der organismen, Zweiter Band: Allgemeine Entwicklungsgeschichte der organismen: Berlin, Verlag von Georg Reimer, 160 p.Google Scholar
Hintze, L.F., 1973, Lower and Middle Ordovician stratigraphic sections in the Ibex Area, Millard County, Utah: Brigham Young University Geology Studies, v. 20, p. 336.Google Scholar
Hotchkiss, F.H.C., 2009, Arm stumps and regeneration models in Asteroidea (Echinodermata): Proceedings of the Biological Society of Washington, v. 122, p. 342354.CrossRefGoogle Scholar
Hotchkiss, F.H.C., 2012, Growth zones and extraxial-axial skeletal homologies in Asteroidea (Echinodermata): Proceedings of the Biological Society of Washington, v. 125, p. 106121.CrossRefGoogle Scholar
Jaekel, O., 1903, Asteriden und Ophiuriden aus dem Silur Böhmens: Zeitschrift der Deutschen Geologischen Gesellschaft, v. 55, p. 106113.Google Scholar
Jaekel, O., 1923, Zur morphogenie der Asterozoa: Palaeontologischen Zeitschrift, v. 5, p. 344350.CrossRefGoogle Scholar
Jell, P.A., 2014, A Tremadocian asterozoan from Tasmania and a late Llandovery edrioasteroid from Victoria. Alcheringa: An Australasian Journal of Palaeontology, doi, p. 10.1080/03115518.2014.911642.CrossRefGoogle Scholar
Lehmann, W.M., 1957, Die Asterozoen in den Dachschiefern des rheinischen Unterdevons: Abhandlungen des Hessischen Landesamtes für Bodenforschung, v. 21, 160 p.Google Scholar
McCoy, F., 1851, in Sedgwick, A., and McCoy, F., 1851–1857, A systematic description of the british palaeozoic fossils in the Geological Museum of the University of Cambridge: London and Cambridge, 611 p.Google Scholar
McKnight, D.G., 1975, Classification of somasteroids and asteroids (Asterozoa: Echinodermata): Journal of the Royal Society of New Zealand, v. 5, p. 1319.CrossRefGoogle Scholar
Madsen, F.J., 1966, The Recent sea-star Platasterias and the fossil Somasteroidea: Nature, v. 209, p. 1367.CrossRefGoogle Scholar
Mooi, R., and David, B., 1998, Evolution within a bizarre phylum: homologies of first echinoderms: American Zoologist, v. 38, p. 965974.CrossRefGoogle Scholar
Mooi, R., and David, B., 2000, What a new model of skeletal homologies tells us about asteroid evolution: American Zoologist, v. 40, p. 326339.Google Scholar
Mooi, R., David, B., and Marchand, D., 1994, Echinoderm skeletal homologies: classical morphology meets modern phylogenetics, in David, B., Guille, A., Féral, J.-P., and Roux, M., eds., Echinoderms through time, proceedings of the Eighth International Echinoderm Conference, Dijon, France: Rotterdam, A.A. Balkema, p. 87–95.CrossRefGoogle Scholar
Patterson, C., 1988, Homology in classical and molecular biology: Molecular Biology and Evolution, v. 5, p. 603625.Google ScholarPubMed
Salter, J.W., 1857, On some new Palaeozoic star-fishes: Annals and Magazine of Natural History, Series 2, v. 20, p. 321334.CrossRefGoogle Scholar
Smith, A.B., and Jell, P.A., 1990, Cambrian edrioasteroids from Australia and the origin of starfishes: Memoirs of the Queensland Museum, v. 28, p. 715778.Google Scholar
Shackleton, J.D., 2005, Skeletal homologies, phylogeny and classification of the earliest asterozoan echinoderms: Journal of Systematic Palaeontology, v. 3, p. 29114.CrossRefGoogle Scholar
Spencer, W.K., 1914, The British Palaeozoic Asterozoa: Palaeontographical Society of London Monograph, Pt. 1 (for 1913), p. 156.Google Scholar
Spencer, W.K., 1916, The British Palaeozoic Asterozoa: Palaeontographical Society of London Monograph, Pt. 2 (for 1915), p. 57108.CrossRefGoogle Scholar
Spencer, W.K., 1927, The British Palaeozoic Asterozoa: Palaeontographical Society of London Monograph, Pt. 7 (for 1925), p. 325388.CrossRefGoogle Scholar
Spencer, W.K., 1940, The British Palaeozoic Asterozoa: Palaeontographical Society of London Monograph, Pt. 10 (for 1940), p. 495540.CrossRefGoogle Scholar
Spencer, W.K., 1951, Early Palaeozoic starfish: Philosophical Transactions of the Royal Society B, v. 235, p. 87129.Google ScholarPubMed
Spencer, W.K., and Wright, C.W., 1966, Asterozoans: U4-U107, in Moore, R.C., ed. Treatise on invertebrate paleontology, pt. U, Echinodermata 3(1): Lawrence, The Geological Society of America and The University of Kansas.Google Scholar
Sprinkle, J., and Collins, D., 2007, Revision of Echmatocrinus from the Middle Cambrian Burgess Shale of British Columbia: Lethaia, v. 31, p. 269282.CrossRefGoogle Scholar
Stürtz, B., 1900, Ein weiter Beitrag zur Kenntnis palaeozoischer Asteroiden: Verhandlungen des naturhistorischen vereins der preussischen Rheinlande und Westfalens, v. 56, p. 176240.Google Scholar
Swofford, D.L., 1998. PAUP*. Phylogenetic analysis using parsimony (*and other methods), version 4: Sunderland, Massachusetts, Sinauer Associates.Google Scholar
Thoral, M., 1935, Deuxième Thèse. Contribution à l’étude paléontologique de l’Ordovicien inférieur de la Montagne Noire et Révision sommaire de la faune cambrienne de la Montagne Noire, Sér. A, no. 1541, no. D’Ordre, p. 2407: Montpellier, Imprimerie de la manufacture de la charité (Pierre-Rouge), 363 p.Google Scholar
Tortello, M.F., Vizcaïno, D., and Álvaro, J.J., 2006, Early Ordovician agnostoid trilobites from the southern Montagne Noire, France: Journal of Paleontology, v. 80, p. 477495.CrossRefGoogle Scholar
Vizcaïno, D., and Lefebvre, B., 1999, Les échinodermes du Paléozoïque Inférieur de Montagne Noire: Biostratigraphie et Paléodiversité: Geobios, v. 32, p. 353364.Google Scholar
Westgate, L.G., and Knopf, A., 1932, Geology and ore deposits of the Pioche District, Nevada: U.S. Geological Survey Professional Paper, v. 171, 79 p.Google Scholar
Zhao, Y., Sumrall, C.D., Parsley, R.L., and Peng, J., 2010, Kailidiscus, a new plesiomorphic edrioasteroid from the basal Middle Cambrian Kaili Biota of Guizhou Province, China: Journal of Paleontology, v. 84, p. 668680.CrossRefGoogle Scholar
Zittel, K.A., 1895, Grundzüge der Palaeontologie (Palaeozoologie): Munich, R. Oldenbourg, 971 p.Google Scholar