Abstract
The new Tremadoc cornute,Flabellicystis rushtoni n. gen. n. sp., from the Shineton Shale Formation of Shropshire is described and reconstructed. The description is based on three articulated individuals preserved as moulds. The oldest cornutes are Middle Cambrian in age but only few species are known from sediments older than Arenig; the description of the new cornute is therefore a significant contribution to our knowledge of the early diversity and evolution of the group. BecauseFlabellicystis rushtoni is the second cornute described from Tremadoc sediments, it constitutes as well an important link between the Cambrian and the Arenig forms. A new cladistic analysis of the group Cornuta placesFlabellicystis between the Cambrian speciesPonticulocarpus robisoni and the Arenig genusChauvelicystis. The three genera share a similar basic design, almost identical marginal plating, a flat lower surface and an expanded, fan-like plate surrounding the anal lobe.
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Literature
Arendt, D. &Nübler-Jung, K. 1994. Inversion of dorsoventral axis? - Nature371 (6492): 26.
Berg-Madsen, V. 1986. Middle Cambrian cystoid t(ensu lato system columnals from Bornholm, Denmark. - Lethaia19 (1): 67–80.
Bergström, J.;Naumann, W.W.;Viehweg, J. &Martí Mus, M. 1998. Conodonts, calcichordates and the origin of vertebrates. - Mitteilungen aus dem Museum für Naturkunde in Berlin, Geowissenschaftliche Reihe1 (1998): 81–92.
Bromham, L.D. &Degnan, B.M. 1999. Hemichordates and deuterostome evolution: robust molecular phylogenetic support for a hemichordate + echinoderm clade. - Evolution & Development1 (3): 166–171.
Chauvel, J. 1966. Echinodermes de l’Ordovicien du Maroc. - Cahiers de Paléontologie1966: 1–112.
Chauvel, J. 1986.Milonicystis kerfornei n. gen. n. sp. un nouvel echinoderme homalozoaire de l’Ordovicien armoricain. - Hercynica2(1): 79–81.
Chauvel, J. 1971. Les Echinodermes Carpoïdes du Paléozoïque inférieur marocain. - Notes Service géologique du Maroc31 (237): 49–60.
Chauvel, J. &Nion, J. 1997. Echinodermes (Homalozoa: Cornuta et Mitrata) noveaux pour l’Ordovicien du Massif Armoricain et conséquences paléogéographiques. - Géobios10 (1): 35–49.
Cripps, A.P. 1988. A new species of stem-group chordate from the Upper Ordovician of northern Ireland. - Palaeontology31 (4): 1053–1077.
Cripps, A.P. 1989a. Anew stem-group chordate (Cornuta) from the Llandeilo of Czechoslovakia and the cornute-mitrate transition. - Zoological Journal of the Linnean Society96: 49–85.
Cripps, A.P. 1989b. A new genus of stem chordate (Cornuta) from the Lower and Middle Ordovician of Czechoslovakia and the origin of bilateral symmetry in the chordates. - Géobios22 (2): 215–245.
Cripps, A.P. 1991. A cladistic analysis of the cornutes (stemchordates). - Zoological Journal of the Linnean Society102: 333–666.
Cripps, A.P. &Daley, P.E.J. 1994. Two cornutes from the Middle Ordovician (Llandeilo) of Normandy, France, and the reinterpretationof Milonicystis kerfornei. - Palaeontographica, (A)232 (4–6): 99–132.
Daley, P.E.J. 1992. Two new cornutes from the Lower Ordovician of Shropshire and southern France. - Palaeontology35(1): 127–148.
David, B.;Lefebvre, B.;Mooi, R. &Parsley, R. 2000. Are homalozoans echinoderms? An answer from the extraxialaxial theory. - Paleobiology26 (4): 529–555.
Derstler, K. 1979. Biogeography of the stylophoran carpoids (Echinodermata). -In:Gray, J. &Boucot, A.J., eds., Historical Biogeography, Plate tectonics, and the Changing Environment: 91–109, Corvallis/Oregon (Oregon University Press).
Fisher, D.C. 1982. Stylophoran skeletal crystallography: testing the calcichordate theory of vertebrate origins. -Geological Society of America, Abstracts with programs14 (7): 488.
Fleming, J. 1828. A History of British Animals, exhibiting the descriptive Characters and systematical Arrangement of the Genera and Species of Quadrupeds, Birds, Reptiles, Fishes, Mollusca, and Radiata of the United Kingdom. - 565 p., Edinburgh (Bell & Bradfutes).
Fortey, R.A. &Owens, R.M. 1991. A trilobite fauna from the highest Shineton Shales in Shropshire and the correlation of the latest Tremadoc. - Geological Magazine128 (5): 437–434.
Franzen, C. 1997. Middle Cambrian echinoderms from south central Sweden. - Geological Society of America, Abstracts with programs29 (6): 98.
Gil Cid, M.D.;Domínguez Alonso, P.;Silván Pobes, E. &Escribano Ródenas, M. 1996.Bohemiaecystis jefferiesi n. sp.; primer Cornuta para el Ordovícico Español. -Estudios geológicos52: 313–326.
Gill, E.D. &Caster, K.E. 1960. Carpoid echinoderms from the Silurian and Devonian of Australia. -Bulletins of American Paleontology41: 5–71.
Guensburg, T.E. &Sprinkle, J. 2000. Ecologic radiation of Cambro-Ordovician echinoderms. - In:Zhuravlev, A. Yu. &Riding, R., eds., The Ecology of the Cambrian Radiation: 428–444, New York (Columbia University Press).
Jaekel, O. 1901. Über Carpoideen, eine neue Klasse von Pelmatozoen. - Zeitschrift der Deutschen Geologischen Gesellschaft52: 661–677.
Jefferies, R.P.S. 1968. The subphylum Calcichordata (Jefferies 1967) - primitive fossil chordates with echinoderm affinities.- Bulletin of the British Museum (Natural History), Geology16: 243–339.
Jefferies, R.P.S. 1969.Ceratocystis perneri Jaekel - A middle Cambrian chordate with echinoderm affinities. -Palaeontology12 (3): 494–535.
Jefferies, R.P.S. 1986. The ancestry of the vertebrates. - 376 pp., London (British Museum, Natural History).
Jefferies, R.P.S. &Brown, N.A. 1995: Dorsoventral axis inversion? - Nature374 (6517): 22.
Jefferies, R.P.S.;Brown, N.A. &Daley, P.E.J. 1996: The early phylogeny of chordates and echinoderms and the origin of chordate left-right asymmetry and bilateral symmetry. - Acta Zoologica (Stockholm)77 (2): 101–122.
Jefferies, R.P.S. &Jacobson, A.G. 1998. An episode in the ancestry of vertebrates: from mitrate to crown-group craniate. - Integrative Biology: Issues, News, and Reviews1(4): 115–132.
Jefferies, R.P.S.;Lewis, M. &Donovan, S.K. 1987.Protocystites menevensis - A stem-group chordate (Cornuta) from the Middle Cambrian of South Wales. - Palaeontology30 (3): 429–484.
Jefferies, R.P.S. &Prokop, R.J. 1972. A new calcichordate from the Ordovician of Bohemia and its anatomy, adaptations and relationships. - Biological Journal of the Linnean Society4 (2): 69–115.
Kolata, D.R.;Frest, T.J. &Mapes, R.H. 1991. The youngest carpoid: ocurrence, affinities, and life mode of a Pennsylvanian (Morrowan) mitrate from Oklahoma. - Journal of Paleontology65 (5): 844–855.
Lefebvre, B. 2000. Homologies in Stylophora: a test of the “Calcichordate Theory”. - Géobios33 (3): 359–364.
Lefebvre, B.;Racheboeuf, P. &David, B. 1998. Homologies in stylophoran echinoderms. - In:Mooi, R. &Telford, M., eds., Echinoderms: San Francisco: 103–109, Rotterdam (Balkema).
Lefebvre, B. &Vizcaino, D. 1999. New Ordovician cornutes (Echinodermata, Stylophora) from Montagne Noire and Brittany (France) and a revision of the order Cornuta Jaekel 1901. -Géobios32 (3): 421–458.
Nübler-Jung, K. &Arendt, D. 1999. Dorsoventral axis inversion: Enteropneust anatomy links invertebrates to chordates turned upside down. - Journal of Zoological Systematics and Evolutionary Research37 (2): 93–100.
Parsley, R.L. 1988. Feeding and respiratory strategies in Stylophora. - In:Paul, C.R.C. &Smith, A.B., eds., Echinoderm phylogeny and evolutionary biology: 347–361, Oxford (Clarendon Press).
Parsley, R.L. 1997. The echinoderm classes Stylophora and Homoiostelea: non Calcichordata. - Paleontological Society Papers3: 225–248.
Parsley, R.L. 1998. Taxonomic revision of the Stylophora. - In:Mooi, R. &Telford, M., eds., Echinoderms: San Francisco: 111–117, Rotterdam (Balkema).
Ruta, M. 1999. Brief review of the Stylophoran debate. - Evolution & Development1 (2): 123–135.
Sumrall, C.D. &Sprinkle, J. 1999.Ponticulocarpus, a new cornute-grade stylophoran from the Middle Cambrian Spence Shale of Utah. - Journal of Paleontology,73 (5): 886–891.
Sumrall, C.D.;Sprinkle, J. &Guensburg, T.E. 1997. Systematics and paleoecology of Late Cambrian echinoderms from the western United States. - Journal of Paleontology,71 (6): 1091–1109.
Swofford, D.L. 1993. PAUP: Phylogenetic Analysis Using Parsimony, Version 3.1.1. - 255 pp., Chapaign/Illinois (Illinois Natural History Survey).
Ubaghs, G. 1963.Cothurnocystis Bather,Phyllocystis Thoral and an undeterminated member of the order soluta (Echinodermata, Carpoidea) in the upper-most Cambrian of Nevada. - Journal of Paleontology37 (6): 1133–1142.
Ubaghs, G. 1967. Le genreCeratocystis Jaekel (Echinodermata, Stylophora). Paleontological Contributions University of Kansas22: 1–16.
Ubaghs, G. 1968. Stylophora. - In:Moore, R.C., ed., Treatise on Invertebrate Paleontology, Part S (1967): S297-S650, Lawrence/Kansas (Geological Society of America & University of Kansas Press).
Ubaghs, G. 1969. Les échinodermes carpoides de l’Ordovicien inférieur de la Montagne Noire (France). -Cahiers de Paléontologie1969: 1–110.
Ubaghs, G. 1975. Early Paleozoic echinoderms. -Annual Review of Earth and Planetary Sciences3: 79–98.
Ubaghs, G. 1981. Reflexions sur la nature et la fonction de l’appendice articulé des carpoides Stylophora (Echinodermata). -Annales de Paléontologie (Invertébrés)67: 33–48.
Ubaghs, G. 1983. Echinodermata. Notes sur les échinodermes de l’ordovicien inférieur de la Montagne Noire (France). - In:Courtessole, R.;Marek, L.;Pillet, J.;Ubaghs, G. &Vizcaino, D., eds., Calymenina, Echinodermata et Hyolitha de l’Ordovicien de la Montagne Noire (France Méridionale): 33–55, Carcassonne (Société d’Etudes Scientifiques de l’Aude).
Ubaghs, G. 1987. Échinodermes nouveaux du Cambrien Moyen de la Montagne Noire (France). - Annales de Paléontologie (Vertébrés-Invertébrés)73 (1): 1–27.
Ubaghs, G., 1991. Deux Stylophora (Homalozoa, Echinodermata) nouveaux pour l’Ordovicien inférieur de la Montagne Noire (France Meridionale). - Paläontologische Zeitschrift65: 157–171.
Ubaghs, G. 1994. Échinodermes nouveaux (Stylophora, Eocrinoidea) de l’Ordovicien inférieur de la Montagne Noire (France). - Annales de Paléontologie (VertébrésInvertébrés)80 (2): 107–141.
Ubaghs, G. 1999. Échinodermes nouveaux du Cambrien supérieur de la Montagne Noire (France méridionale). - Géobios31 (6): 809–829.
Ubaghs, G. &Robison, R.A. 1988. Homalozoan echinoderms of the Wheeler Formation (Middle Cambrian) of western Utah. - The University of Kansas Paleontological Contributions (Papers)120: 1–17.
Woods, I.S. &Jefferies, R.P.S. 1992. Anew stem-group chordate from the Lower Ordovician of south Wales, and the problem of locomotion in boot-shaped cornutes. - Palaeontology35: 1–25.
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Mus, M.M. The Ordovician cornuteFlabellicystis rushtoni n. gen. n. sp. (Stylophora, Echinodermata) and its phylogenetic position within the group Cornuta. Paläont. Z. 76, 99–116 (2002). https://doi.org/10.1007/BF02988189
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DOI: https://doi.org/10.1007/BF02988189