Skip to main content
×
×
Home

Morphological disparity and systematic revision of the eocrinoid genus Rhopalocystis (Echinodermata, Blastozoa) from the Lower Ordovician of the central Anti-Atlas (Morocco)

  • Ninon Allaire (a1) (a2), Bertrand Lefebvre (a2), Elise Nardin (a3), Emmanuel L.O. Martin (a2), Romain Vaucher (a2) and Gilles Escarguel (a4)...
Abstract
Abstract

The genus Rhopalocystis (Eocrinoidea, Blastozoa) is characterized by both a short stratigraphic range (Fezouata Shale, middle Tremadocian to middle Floian, Lower Ordovician) and a reduced geographic extension (Agdz-Zagora area, central Anti-Atlas, Morocco). Since the original description of its type species (R. destombesi Ubaghs, 1963), three successive revisions of the genus Rhopalocystis have led to the erection of nine additional species. The morphological disparity within this genus is here critically reassessed on the basis of both historical material and new recently collected samples. The detailed examination of all specimens, coupled with morphometric and cladistic analyses, points toward a relatively strong support for five morphotypes. A systematic revision of Rhopalocystis is thus suggested, with only five valid taxa: R. destombesi, R. fraga Chauvel, 1971, R. grandis Chauvel, 1971, R. havliceki Chauvel, 1978, and R. zagoraensis Chauvel, 1971. The five others are considered as junior synonyms (R. dehirensis Chauvel and Régnault, 1986, R. lehmani Chauvel and Régnault, 1986, R. sp. A, R. sp. B, and R. sp. C).

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Morphological disparity and systematic revision of the eocrinoid genus Rhopalocystis (Echinodermata, Blastozoa) from the Lower Ordovician of the central Anti-Atlas (Morocco)
      Available formats
      ×
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about sending content to Dropbox.

      Morphological disparity and systematic revision of the eocrinoid genus Rhopalocystis (Echinodermata, Blastozoa) from the Lower Ordovician of the central Anti-Atlas (Morocco)
      Available formats
      ×
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about sending content to Google Drive.

      Morphological disparity and systematic revision of the eocrinoid genus Rhopalocystis (Echinodermata, Blastozoa) from the Lower Ordovician of the central Anti-Atlas (Morocco)
      Available formats
      ×
Copyright
References
Hide All
Akaike H., 1974, A new look at the statistical model identification: IEEE Transactions on Automatic Control, v. 19, no. 6, p. 716723.
Allaire N., Lefebvre B., Martin E., Nardin E., and Vaucher R., 2015, Taphonomy of new Rhopalocystis assemblages in the Lower Ordovician of the Zagora area (central Anti-Atlas, Morocco), in Zamora, S., and Rabano, I., eds., Progress in Echinoderm Palaeobiology: Cuadernos del Museo Geominero, v. 19, p. 2126.
Ausich W.I., Rhenberg E.C., Kammer T.W., and Deline B., 2013, Rooting the early crinoid diversification with the eocrinoid Rhopalocystis : Geological Society of America Abstracts with Programs, v. 45, no. 7, p. 109.
Ausich W.I., Kammer T.W., Rhenberg E.C., and Wright D.F., 2015, Early phylogeny of crinoids within the pelmatozoan clade: Palaeontology, v. 58, no. 6, p. 937952.
Barrande J., 1887, Système Silurien du Centre de la Bohême: Volume VII. Classe des Echinodermes, Ordre des Cystidées: Prague, Rivnac, 233 p.
Broadhead T.W., 1982, Reappraisal of class Eocrinoidea (Echinodermata), in Lawrence, J.M., ed., Echinoderms, Proceedings of the International Conference, Tampa Bay: Rotterdam, Balkema, pp. 125–131.
Chauvel J., 1941, Recherche sur les cystoïdes et les carpoïdes armoricains: Mémoires de la Société géologique et minéralogique de Bretagne, v. 5, p. 1286.
Chauvel J., 1971, Rhopalocystis Ubaghs: un échinoderme éocrinoïde du Trémadocien de l’Anti-Atlas marocain: Mémoires du Bureau de Recherches Géologiques et Minières, v. 73, p. 4349.
Chauvel J., 1978, Compléments sur les échinodermes du Paléozoïque marocain (diploporites, éocrinoïdes, édrioastéroïdés): Notes et Mémoires du Service géologique du Maroc, v. 272, p. 2778.
Chauvel J., and Régnault S., 1986, Variabilité du genre Rhopalocystis Ubaghs, éocrinoïde du Trémadocien de l’Anti-Atlas marocain: Geobios, v. 19, p. 863870.
Clausen S., 2004, New early Cambrian eocrinoids from the Iberian Chains (NE Spain) and their role in nonreefal benthic communities: Eclogae Geologicae Helvetiae, v. 97, no. 3, p. 371379.
Clavel J., Merceron G., and Escarguel G., 2014, Missing data estimation in morphometrics: How much is too much?: Systematic Biology, v. 63, no. 2, p. 203218.
Dempster A.P., Laird N.M., and Rubin D.B., 1977, Maximum likelihood from incomplete data via the EM algorithm: Journal of the Royal Statistical Society, Series B (methodological), v. 39, no. 1, p. 138.
Destombes J., 1962, Stratigraphie et paléogéographie de l’Ordovicien de l’Anti-Atlas (Maroc): un essai de synthèse: Bulletin de la Société géologique de France, v. 4, p. 453460.
Destombes J., 1971, L’Ordovicien au Maroc. Essai de synthèse stratigraphique: Mémoire du Bureau de Recherche Géologique Minière, v. 73, p. 237263.
Destombes J., 2006, Carte géologique au 200 000° de l’Anti-Atlas marocain. Paléozoïque inférieur: Cambrien moyen et supérieur - Ordovicien - base du Silurien. Sommaire général sur les mémoires explicatifs des cartes géologiques au 1/200 000 de l’Anti-Atlas marocain: Notes et Mémoires du Service géologique du Maroc, v. 515, p. 1150.
Destombes J., Hollard H., and Willefert S., 1985, Lower Palaeozoic rocks of Morocco, in Holland, C.H., ed., Lower Palaeozoic Rocks of the World. 4. Lower Palaeozoic of North Western - Central Africa: New York, Wiley, p. 91336.
Felsenstein J., 2005, PHYLIP (Phylogeny Inference Package) version 3.6: Distributed by the author, Department of Genome Sciences, University of Washington, Seattle.
Frest T.J, 2005, Ampheristocystis, a Silurian (lower Wenlock) eocrinoid (Echinodermata, Blastozoa) from Indiana: Geological Journal, v. 40, no. 3, p. 301329.
Guensburg T.E., and Sprinkle J., 2007, Phylogenetic implications of the Protocrinoida: Blastozoans are not ancestral to crinoids: Annales de Paléontologie, v. 93, no. 4, p. 277290.
Guensburg T.E, Blake D.B., Sprinkle J., and Mooi R., 2016, Crinoid ancestry without blastozoans: Acta Palaeontologica Polonica, v. 61, no. 2, p. 253256.
Gutiérrez-Marco J.C., and Martin E., 2016, Biostratigraphy and palaeogeography of Lower Ordovician graptolites from the Fezouata Shale (Moroccan Anti-Atlas): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 3549.
Hammer Ø., Harper D.A.T., and Ryan P.D., 2001, PAST: Paleontological statistics software package for education and data analysis: Palaeontologia Electronica, v. 4, no. 1, 9 p.
Honaker J., King G., and Blackwell M., 2011, Amelia II: A program for missing data: Journal of statistical software, v. 45, no. 7, p. 147.
Jaekel O., 1918, Phylogenie und System der Pelmatozoen: Paläontologische Zeitschrift, v. 3, p. 1128.
Kammer T.W., Sumrall C.D., Zamora S., Ausich W.I., and Deline B., 2013, Oral region homologies in Paleozoic crinoids and other plesiomorphic pentaradial echinoderms: PLoS One, v. 8, no. 11, e77989, p. 1–16.
Lefebvre B., Sumrall C.D., Shroat-Lewis R.A., Reich M., Webster G.D., Hunter A.W., Nardin E., Rozhnov S.V., Guensburg T.E., Touzeau A., Noailles F., and Sprinkle J., 2013, Palaeobiogeography of Ordovician echinoderms, in Harper, D.A.T, and Servais, T., eds., Early Palaeozoic Biogeography and Palaeogeography: Geological Society, London, Memoirs, v. 38, p. 173198.
Lefebvre B., El Hariri K., Lerosey-Aubril R., Servais T., and Van Roy P., 2016a, The Fezouata Shale (Lower Ordovician, Anti-Atlas, Morocco): A historical review: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 723.
Lefebvre B., Allaire N., Guensburg T.E., Hunter A.W., Kouraïss K., Martin E.L.O., Nardin E., Noailles F., Pittet B., Sumrall C.D., and Zamora S., 2016b, Palaeoecological aspects of the diversification of echinoderms in the Lower Ordovician of central Anti-Atlas, Morocco: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 97121.
Lehnert O., Nowak H., Sarmiento G.N., Gutiérrez-Marco J.C., Akodad M., and Servais T., 2016, Conodonts from the Lower Ordovician of Morocco—Contributions to age and faunal diversity of the Fezouata Lagerstätte and peri-Gondwana biogeography: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 5061.
Martin E.L.O., Pittet B., Gutiérrez-Marco J.C., Vannier J., El Hariri K., Lerosey-Aubril R., Masrour M., Nowak H., Servais T., Vandenbroucke T., Van Roy P., Vaucher R., and Lefebvre B., 2016, The Lower Ordovician Fezouata Konservat-Lagerstätte from Morocco: Age, environment and evolutionary perspectives: Gondwana Research, v. 34, p. 274283.
Mosimann J.E., 1970, Size allometry: Size and shape variables with characterizations of the lognormal and generalized gamma distributions: Journal of the American Statistical Association, v. 65, p. 930948.
Nardin E., 2007, La diversification des blastozoaires (Echinodermata) au Paléozoïque inférieur: Aspects phylogénétiques, paléoécologiques et paléobiogéographiques [Ph.D. thesis]: Dijon, Université de Bourgogne, 532 p.
Noailles F., Lefebvre B., Guensburg T.E., Hunter A.W., Nardin E., Sumrall C.D., and Zamora S., 2010, New echinoderm-Lagerstätten from the Lower Ordovician of central Anti-Atlas (Zagora area, Morocco): A Gondwanan perspective of the Great Ordovician Biodiversification Event, in Reich, M., Reitner, J., Roden, V., and Thuy, B., eds., Echinoderm Research 2010: Göttingen, Universitätsverlag Göttingen, p. 7778.
Nowak H., Servais T., Pittet B., Vaucher R., Akodad M., Gaines R.R., and Vandenbroucke T., 2016, Palynomorphs of the Fezouata Formation (Lower Ordovician, Morocco): Age and environmental constraints of the Fezouata Biota: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 6274.
Paul C.R.C., 1988, The phylogeny of the cystoids, in Paul, C.R.C., and Smith, A.B., eds., Echinoderm Phylogeny and Evolutionary Biology: Oxford, Clarendon Press, p. 199213.
Smith A.B., 1988, Patterns of diversification and extinction in Early Palaeozoic echinoderms: Palaeontology, v. 31, p. 799828.
Sprinkle J., 1973, Morphology and Evolution of Blastozoan Echinoderms: Cambridge, MA, Museum of Comparative Zoology Harvard University, 284 p.
Sprinkle J., and Guensburg T.E, 2001, Growing a stalked echinoderm within the extraxial axial theory, in Barker, M., ed., Echinoderms 2000: Proceedings of the 10th International Echinoderm Conference, Dunedin: Lisse, Netherlands, AA Balkema, p. 59–65.
Sumrall C.D., Sprinkle J., and Guensburg T.E., 2001, Comparison of flattened blastozoan echinoderms: Insights from the new Early Ordovician eocrinoid Haimacystis rozhnovi : Journal of Paleontology, v. 75, no. 5, p. 985992.
Ubaghs G., 1963, Rhopalocystis destombesi n. g., n. sp., éocrinoïde de l’Ordovicien inférieur (Trémadocien supérieur) du Sud marocain: Notes et Mémoires du Service géologique du Maroc, v. 172, p. 2545.
Ubaghs G., 1968, Eocrinoidea, in Moore, R.C., ed., Treatise on Invertebrate Paleontology, Part S. Echinodermata 1., Lawrence, Geological Society of America and University of Kansas Press, p. S495S565.
Vaucher R., Martin E.L.O., Hormière H., and Pittet B., 2016, A genetic link between Konzentrat and Konservat Lagerstätten in the Fezouata Formation (Lower Ordovician, Morocco): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 460, p. 2434.
Vaucher R., Pittet B., Hormière H., Martin E., and Lefebvre B., 2017, A wave-dominated, tide-modulated model for the Lower Ordovician of the Anti-Atlas, Morocco: Sedimentology, v. 64, no. 3, p. 777807, doi: 10.1111/sed.12327.
Vidal M., 1996, Le modèle des biofaciès à trilobites: Un test dans l’Ordovicien inférieur de l’Anti-Atlas, Maroc: Compte-Rendus de l’Académie des Sciences, Paris, v. 327, p. 327333.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Paleontology
  • ISSN: 0022-3360
  • EISSN: 1937-2337
  • URL: /core/journals/journal-of-paleontology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 24
Total number of PDF views: 106 *
Loading metrics...

Abstract views

Total abstract views: 234 *
Loading metrics...

* Views captured on Cambridge Core between 10th May 2017 - 18th December 2017. This data will be updated every 24 hours.