Abstract
The similarity in the skeleton model of the brachiolar food-gathering system of Blastozoa and the arm system of Crinozoa, including the apical growth with enantomorphous displacement of skeletal ele-ments, is explained by the primary organizing role of the radial ambulacral canals, which have the same branching model for ambulacral tentacles. The difference in the positions of brachioles and arms relative to the theca (exothecal and endothecal) is associated with the formation of the primary ambulacral tentacles directly on the body surface of the majority of Blastozoa, particularly, the closed vestibular cavity of crinoids. The supporting skeleton of brachioles arose as a branch of the plates covering the floor of the ambulacrum, if they were present, or formed similarly as a new formation outside the theca. The supporting skeleton of arms, brachials, developed as a result of the serial growth of plates positioned radially at the boundary of the aboral skeleton and tegmen formed due to the appearance of the vestibulum. The hypothesis of the inductive role of hydrocoel and its radial ambulacral appendages, which organize the arrangement of skeletal elements in the morphogenesis of echinoderms, enables the refinement of the principle of skeleton division into the axial and extraxial parts. The axial skeleton has a developmental model formed under the control of the radial ambu-lacral canals. Remaining skeleton is extraxial, subdivided into the symmetrized part arranged under direct or indirect organizing effect of the hydrocoel and unregulated, nonsymmetrized part, which is not connected initially with the influence of the hydrocoel.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Amemiya, S., Omori, A., Tsurugaya, T., Hibino, T., Yamaguchi, M., Kuraishi, R., Kiyomoto, M., and Monokawa, T., Early stalked stages in ontogeny of the living isocrinid sea lily Metacrinus rotundus, Acta Zool. Stockholm, 2016, no. 97. pp. 102–116.
Barrois, J., Development de la comatule (C. mediterranea), Rec. Zool. Suisse, 1888, vol. 8, pp. 477–484.
Beloussov, L.V., Osnovy obshchei embriologii (Fundamentals of General Embryology), Moscow: Mosk. Gos. Univ., 1993.
Breimer, A., Recent crinoids, in Treatise on Invertebrate Paleontology: Part T. Echinodermata 2, Lawrence: Geol. Soc. Am.; Univ. Kansas Press, 1978, vol. 1, pp. 316–330.
David, B. and Mooi, R., Major events in the evolution of echinoderms viewed by the light of embryology, in Echino-derms: San Francisco: Proceedings of the 9th International Echinoderm Conference, Mooi, R. and Telford, M., Eds., Rotterdam: A.A. Balkema, 1998, pp. 21–28.
David, B. and Mooi, R., How Hox genes can shed light on the place of echinoderms among the deuterostomes, Evodevo, 2014, vol. 5, no. 22, (doi: 10.1186/2041-9139-5-22).
Engle, S., Ultrastructure and development of the body cav-ities in Antedon bifida (Pennant, 1777) (Comatulida, Crinoidea), Unpublished PhD Thesis (http://edocs.fu-ber-lin.de/diss/receive/ FUDISS_thesis_000000040355).
Gilbert, S.F., Developmental Biology, 9th ed., 2010.
Gislén, T., Echinoderm studies, Zool. Bidrag Fran Uppsala, 1924, vol. 9, pp. 13–16.
Guensburg, T.E., Mooi, R., Sprinkle, J., David, B., and Lefebvre, B., Pelmatozoan arms from the mid-Cambrian of Australia: Bridging the gap between brachioles and brachi-als? Comment: There is no bridge, Lethaia, 2010, vol. 43, pp. 432–440.
Hyman, L.H., The Invertebrates: Echinodermata, New York: McGraw-Hill, 1955.
Ivanov, A.V., Monchadskii, A.S., Polyanskii, Yu.I., and Strelkov, A.A., Bol’shoi praktikum po zoologii bespozvonoch-nykh (Major Practical Training in Invertebrate Zoology), Moscow: Sovet. Nauka, 1946, part 2.
Ivanova-Kazas, O.M., Sravnitel’naya embriologiya bespoz-vonochnykh zhivotnykh. Iglokozhie i polukhordovye (Com-parative Embryology of Invertebrates: Echinodermata and Hemichordata), Moscow: Nauka, 1978.
Kammer, T.W., Bartels, C., and Ausich, W.I., Presumed postlarval pentacrinoids from the Lower Devonian Hunsruck Slate, Berlin, Germany: Lethaia, 2015.
Kraus, Yu.A., Inductive activity of the posterior tip of plan-ula in the marine hydroid Dynamena pumila, Russ. J. Devel-opm. Biol., 2011, vol. 42, no. 2, pp. 92–100.
Mayorova, T., Kosevich, I., Dulin, N., Savina, E., and Kraus, Y., Organizer regions in marine colonial hydrozo-ans, Zoology, 2015, vol. 118, no. 2, pp. 89–101.
Meyer, D.L., Food and feeding mechanisms: Crinozoa, in Echinoderm Nutrition, Jangoux, M. and Lawrence, J.M., Eds., Rotterdam: Balkema, 1982, pp. 25–42.
Mooi, R. and David, B., Skeletal homologies of echino-derms, Paleontol. Soc. Pap., 1997, vol. 3, pp. 305335.
Mooi, R. and David, B., Radial symmetry, the ante-rior/posterior axis, and echinoderm Hox genes, Ann. Rev. Ecol. Evol. Syst., 2008, no. 39, pp. 43–62.
Nichols, D., Chapter 9. Functional morphology of the water-vascular system, in Physiology of Echinodermata, Boolootian, R.A., Ed., New YorkLondonSydney: Intersci. Publ., 1966, pp. 219–244.
Parsley, R.L. and Mintz, L.W., North American Para-crinoidea: (Ordovician: Paracrinozoa, new Echinoder-mata), Bull. Am. Paleontol., 1975, vol. 68, no. 288, pp. 1115.
Rozhnov, S.V., Hybocrinea, a new crinoid subclass, Dokl. Akad. Nauk SSSR, 1985a, vol. 280, no. 4, pp. 1012–1015.
Rozhnov, S.V., Morphology, symmetry, and taxonomic position of hybocrinid crinoids, Paleontol. Zh., 1985b, no. 2, pp. 416.
Rozhnov, S.V., Crookedness of the stem and crown of pel-matozoan echinoderms as resulting from different kinds of heterochrony, in Echinoderm Research, Rotterdam: Balkema, 1998, pp. 385–390.
Rozhnov, S.V., Morphogenesis and evolution of crinoids and other pelmatozoan echinoderms in the Early Paleo-zoic, Paleontol. J., 2002, vol. 36, suppl. no. 6, pp. S525–S674.
Rozhnov, S.V., Anteroposterior axis of echinoderms and displacement of the mouth in historical and individual development, Izv. Ross. Akad. Nauk, Ser. Biol., 2012a, no. 2, pp. 203–212.
Rozhnov, S.V., Development of symmetry and asymmetry in the early evolution of the echinoderms, Paleontol. J., 2012b, vol. 46, no. 8, pp. 780–792.
Rozhnov, S.V., Symmetry of echinoderms: From initial bilat-erally asymmetric metamerism to pentaradiality, Natur. Sci., 2014, vol. 6, no. 4, pp. 171–183 (http://dx.doi.org/10.4236/ ns.2014.64021).
Rozhnov, S.V., Modularity and heterochronies in the evolu-tion of Metazoa: Paleontological aspect, Paleontol. J., 2015, vol. 49, no. 14, pp. 1546–1560.
Springer, F., On a Trenton echinoderm fauna at Kirk-field, Can. Geol. Surv. Mem., 1911, vol. 15, pp. 1–68.
Springer, F., American Silurian crinoids, Smithson. Inst. Publ., 1926, no. 2871, pp. 12–39.
Sprinkle, J., Morphology and Evolution of Blastozoan Echin-oderms, Harvard University Museum of Comparative Zool-ogy, Special Publication, 19–73.
Sprinkle, J. and Moore, R.C., 1978. Hybocrinida, in Trea-tise on Invertebrate Paleontology: Part T. Echinodermata 2, Lawrence: Geol. Soc. Am.; Univ. Kansas Press, 1978, vol. 2, pp. T564–T574.
Sprinkle, J., Parsley, R.L., Zhao, Y., and Peng, J., Revision of lyracystid eocrinoids from the Middle Cambrian of South China and Western Laurentia, J. Paleontol., 2011, vol. 85, no. 2, pp. 250–255.
Sumrall C.D. A model for elemental homology for the peristome and ambulacra in blastozoan echinoderms, in Echinoderms,. Harris, L.G., Bottger, S.A., Walker, C.W., and Lesser, M.P., Eds., London: Durham CRC Press, 2010, pp. 269–276.
Thompson, W., On the embryology of Antedon rosaceus, Philosoph. Transact. R. Soc. London, 1865, vol. 155, pp. 513–544.
Ubaghs, G., Skeletal morphology of fossil crinoids, in Trea-tise on Invertebrate Paleontology: Part T. Echinodermata 2, Lawrence: Geol. Soc. Am.; Univ. Kansas Press, 1978, vol. 1, pp. T58–T216.
Wolpert, L. and Tickle, Ch., Principles of Development, 4th ed., Oxford: Oxford Univ. Press, 2011.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Rozhnov, S.V. Arms versus brachioles: Morphogenetic basis of similarity and differences in food-gathering appendages of pelmatozoan echinoderms. Paleontol. J. 50, 1598–1609 (2016). https://doi.org/10.1134/S0031030116140069
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0031030116140069