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Implications of a new Early Ordovician asteroid (Echinodermata) for the phylogeny of asterozoans

Published online by Cambridge University Press:  20 May 2016

Daniel B. Blake
Affiliation:
Department of Geology, University of Illinois, Urbana 61801,
Thomas E. Guensburg
Affiliation:
Physical Sciences Division, Rock Valley College, Rockford, Illinois 61111,

Abstract

Eriaster ibexensis n. gen. and sp., from the Ibexian (Lower Ordovician) of Utah, is the oldest-known body-fossil taxon of the class Asteroidea. Although important features are not preserved, the external form of E. ibexensis is suggestive of certain living asteroids and unlike approximately coeval somasteroids. The similar ages of Eriaster and the oldest-known somasteroid challenge the candidacy of the latter as basal to asteroids.

Trace fossils assigned to Asteriacites have been recovered from strata as ancient as Lower Cambrian. Asteriacites from younger strata are considered to represent resting traces of asterozoans. Mode of formation of early representatives is problematic; however, their simple existence raises the possibility of extended pre-Ibexian asterozoan evolution, which could explain the morphological disparity found among the earliest-known body-fossil asterozoans.

Type
Paleontological Notes
Copyright
Copyright © The Paleontological Society 

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References

Alpert, S. P. 1976. Trilobite and star-like trace fossils from the White-Inyo Mountains, California. Journal of Paleontology, 50:226239.Google Scholar
Blake, D. B. 1978. The taxonomic position of the modern sea star Cistina Gray, 1840. Proceedings of the Biological Society of Washington, 91:234241.Google Scholar
Blake, D. B. 1994. Re-evaluation of the Palasteriscidae Gregory, 1900, and the early phylogeny of the Asteroidea (Echinodermata). Journal of Paleontology, 68:123134.Google Scholar
Blake, D. B. 2000. The class Asteroidea (Echinodermata): fossils and the base of the crown group. American Zoologist, 40:316325.Google Scholar
Blake, D. B., and Elliott, D. R. 2003. Ossicular homologies, systematics, and phylogenetic implications of certain North American Carboniferous asteroids. Journal of Paleontology, 77:476489.2.0.CO;2>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, 67:103113.CrossRefGoogle Scholar
Dean, J. 1999. What makes an ophiuroid? A morphological study of the problematic Ordovician stelleroid Stenaster and the paleobiology of the earliest asteroids and ophiuroids. Zoological Journal of the Linnean Society, 126:225250.Google Scholar
de Blainville, H. M. 1830. Zoophytes. Dictionnaire des Sciences Naturelles. F. G. Levrault, Strasbourg, 60 p.Google Scholar
Fell, H. B. 1963. The phylogeny of sea-stars. Philosophical Transactions of the Royal Society, London, B, 246:386435.Google Scholar
Hicks, H. 1873. On the Tremadoc rocks in the neighbourhood of St. David's, South Wales and their fossil contents. Quarterly Journal of the Geological Society of London, 29:3952.Google Scholar
Hintze, L. 1973. Lower and Middle Ordovician stratigraphic sections in the Ibex area, Millard County, Utah. Brigham Young University Geology Studies, 20:336.Google Scholar
Kesling, R. V. 1967. Neopalaeaster enigmaticus, new starfish from Upper Mississippian Paint Creek Formation in Illinois. Contributions from the The Museum of Paleontology, The University of Michigan, 21:7385.Google Scholar
Kesling, R. V. 1969. Three Permian starfish from Western Australia and their bearing on revision of the Asteroidea. Contributions from the The Museum of Paleontology, The University of Michigan, 22:361376.Google Scholar
Mikulás, R. 1992. The ichnogenus Asteriacites: paleoenvironmental trends. Vêstnik Ceského geologického ústavu, 67:423433.Google Scholar
Mooi, R., and David, B. 2000. What a new model of skeletal homologies tells us about asteroid evolution. American Zoologist, 40:326339.Google Scholar
Pringle, J. 1911. Note on the “Lower Tremadoc” rocks of St. David's, Pembrokeshire. The Geological Magazine, 48:556559.Google Scholar
Rasmussen, H. W. 1952. A new Silurian asteroid from Gotland, Sweden. Geologiska Föreningens Stockholm Förhandlingar, 74:1724.Google Scholar
Schlotheim, E. F. 1820. Die Petrefactenkunde auf ihrem jetzigen Standpunkte durch die Beschreibung seiner Sammlung versteinerter und fossiler berreste des Thier-und Pflanzenreiches der Vorwelt erläutert. Becker, Gotha, 437 p.Google Scholar
Schuchert, C. 1915. Revision of Paleozoic Stelleroidea with special reference to North American Asteroidea. Bulletin of the U.S. National Museum, 88, 312 p.Google Scholar
Sladen, W. P. 1889. Report on the Asteroidea collected by the Challenger. Scientific Reports of the Results of the Voyage of the Challenger, Zoology 30, 894 p.Google Scholar
Spencer, W. K. 1916. British Palaeozoic Asterozoa, Pt. 2. Palaeontographical Society of London Memoir, p. 57108.Google Scholar
Spencer, W. K. 1918. British Palaeozoic Asterozoa, Pt. 3. Palaeontographical Society of London Memoir, p. 109168.Google Scholar
Spencer, W. K. 1919. British Palaeozoic Asterozoa, Pt. 4. Palaeontographical Society of London Memoir, p. 169196.Google Scholar
Spencer, W. K. 1951. Early Palaeozoic starfishes. Philosophical Transactions of the Royal Society, London, B, 235:87129.Google Scholar
Spencer, W. K., and Wright, C. W. 1966. Asterozoans, p. U4U107. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Pt. U, Echinodermata 3. Geological Society of America and University of Kansas Press, Lawrence.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. Thèses présentées a la faculté des sciences de l'Université de Paris pour obtenir le grade de docteur ès-sciences naturelles. Série A, No. 1541, No. D'Ordre: 2407. Imprimerie de la Manufacture de la Charité (Pierre-Rouge), Montpellier, 363 p.Google Scholar
Vizcaino, D., and Lefebvre, B. 1999. Les échinodermes du Paléozoique inférieur de Noire: biostratigraphie et paléodiversité. Geobios, 32:353364.Google Scholar
Webby, B. D., Cooper, R. A., Bergstrom, S. M., and Paris, F. 2003. Stratigraphic framework and time slices, p. 4147. In Webby, B. D., Droser, M.L., Paris, F., and Percival, I. (eds.), The Great Ordovician Biodiversification Event. Columbia University Press, New York.Google Scholar