Abstract
The development of bilateral symmetry of echinoid test in the course of exocyclization and phenomena of dissymmetry in the structure of paired interambulacra and apical system are examined. Peculiar metamery is typical of ambulacra, some plates of which are characterized by the similarity symmetry. The operation of translation in each ambulacrum results in the identity of form; however, it does not provide equal coincidence of each plate. The considerable asymmetry of petaloids in some irregular echinoids results from different functions of tube feet in adjacent petaloid rows.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
D’yakonov, A.M., T. 1. Vyp. 1. Fauna Rossii i sopredel’nykh stran (Fauna of Russia and Adjacent Countries), vol. 1, no. 1: Morskie ezhi (Echinoidea). Iglokozhie (Echinodermata) (Sea urchins (Echinoidea): Echinoderms (Echinodermata)), Nasonov, N.V, Ed., Petrograd, 1923.
Fisher, F.G., Spatangoids: Echinoids, in Treatise on Invertebrate Paleontology: Part U. Echinodermata 3, Moore, R.C., Ed., 1966, vol. 2, pp. 543–628.
Ivanova-Kazas, O.M., Sravnitel’naya embriologiya bespozvonochnykh zhivotnykh. Iglokozhie i polukhordovye (Comparative Embryology of Invertebrates: Echinoderms and Hemichordates), Moscow: Nauka, 1978.
Markov, A.V. and Solovjev, A.N., Echinoids of the genus Washitaster (Spatangoida): Morphology and taxonomic position, Paleontol. Zh., 2002, no. 4, pp. 45–56.
McNamara, Plate translocation in spatangoid echinoids: It’s morphological, functional and phylogenetic significance, Paleobiology, 1987, vol. 13, no. 3, pp. 321–325.
Moore, R.C. and Fell, H.B., Homology of echinozoon rays, in Treatise on Invertebrate Paleontology: Part U. Echinodermata 3, Moore, R.C., Ed., 1966, vol. 1, pp. 119–131.
Poslavskaya, N.A. and Moskvin, M.M., Sea urchins, in Atlas verkhnemelovoi fauny Severnogo Kavkaza i Kryma (Atlas of the Upper Cretaceous Fauna of the Northern Caucasus and Crimea), Moskvin, M.M., Ed., Moscow: Vsesoyuzn. Nauchno-Issled. Inst. Prir. Gas., 1959, pp. 242–304.
Poslavskaya, N.A. and Solovjev, A.N., Class Echinoidea (sea urchins): Order Spatangoida, in Osnovy paleontologii. Iglokozhie, gemikhordovye, pogonofjry, shchetinkochelyustnye (Fundamentals of Paleontology: Echinodermata, Hemichordata, Pogonophora, Chaetognatha), Moscow: Nedra, 1964, pp. 174–189.
Solovjev, A.N., Symmetry of the sea urchins Spatangoida, Byull. Mosk. O-va Ispyt. Prir., Otd. Geol., 1983, vol. 58, no. 4, p. 45.
Solovjev, A.N., Evolutionary lineages of some Cretaceous and Cenozoic genera of sea urchins and their interpretation, in Tezisy dokladov 44 sessii Paleontologicheskogo obshchestva (44th Session of the Paleontological Society), St. Petersburg, 1998. Pp. 94–95.
Solovjev, A.N., Semogenesis as an aspect of phylogenesis and its significance for stratigraphy (using sea urchins as an example), in Materialy 55 sessii Paleontologicheskogo obshchestva (55th Session of the Paleontological Society), St. Petersburg, 2009, pp. 140–142.
Solovjev, A.N. and Markov, A.V., Early evolutionary stages of irregular sea urchins, in Ekosistemnye perestroiki i evolyutsiya biosfery (Ecosystem Reorganizations and Evolution of the Biosphere), Barskov, I.S., Leonova, T.B., and Ponomarenko, A.G., Eds., Moscow: Paleontol. Inst. Ross. Akad. Nauk, 2004, vol. 6, pp. 77–86.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Solovjev, A.N. Symmetry, asymmetry, and dissymmetry in echinoids. Paleontol. J. 48, 1237–1242 (2014). https://doi.org/10.1134/S0031030114120119
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0031030114120119