Paleontological Journal

, Volume 52, Issue 14, pp 1701–1709 | Cite as

Biotic Crises and Giantism of Radiolarian Skeletons in the Late Paleozoic

  • M. S. AfanasievaEmail author


The phenomenon of giantism and minimalism in the skeleton of Late Paleozoic radiolarians is very unusually and has not yet been studied. However, this is not ugliness, but inherited morphological features, probably reflecting environmental influences and habitats. The analysis of 618 radiolarian skeletons has shown (1) inverse role of giant and small individuals in the Devonian (2% of giants and 11.7% of dwarfs) and Carboniferous–Permian (22.5% of giants and 2.2% of dwarfs); (2) a general trend toward increasing maximum conditional diameter of a conditional cell, which became 11 times greater, changing from 2% in the Devonian to 21.5% in the Carboniferous–Permian. This trend toward increasing size of skeletons and giantism in Late Paleozoic radiolarians could have indicated degeneration and reflected decline of radiolarians before mass extinction at the boundaries of the Devonian and Carboniferous (97.8% of species), Permian and Triassic (99.0% of species).


Radiolaria giantism and minimalism of skeletons mass extinction Late Paleozoic 



I am sincerely grateful to A.S. Alekseev for advisable discussion on the manuscript and valuable remarks and to G.S. Rautian for translation of the present paper into English.

This study was supported by the Program of the Presidium of the Russian Academy of Science “Evolution of the Organic World and Planetary Processes.”


  1. 1.
    Afanasieva, M.S. and Amon, E.O., Radiolyarii (Radiolarians), Moscow: Paleontol. Inst. Ross. Akad. Nauk, 2006.Google Scholar
  2. 2.
    Afanasieva, M.S., Amon, E.O., Agarkov, Yu.V., and Boltovskoy, D.S., Radiolarians in the geological record, Paleontol. J., 2005, vol. 39, suppl. no. 3, pp. S135–S392.Google Scholar
  3. 3.
    Anderson, O.R., Radiolaria, Biochem. Physiol. Protozoa, 1980, vol. 10, no. 3, pp. 1–42.Google Scholar
  4. 4.
    Anderson, O.R., Radiolarian fine structure and silica deposition, in Silicon and Siliceous Structures in Biological Systems, Simpson, T.L. and Volcani, B.E., Eds., New York: Springer, 1981, pp. 347–380.Google Scholar
  5. 5.
    Anderson, O.R., Radiolaria, New York: Springer, 1983.CrossRefGoogle Scholar
  6. 6.
    Barskov, I.S., Boiko, M.S., Konovalova, V.A., Leonova, T.B., and Nikolaeva, S.V., Cephalopods in the marine ecosystems of the Paleozoic, Paleontol. J., 2008, vol. 42, no. 11, pp. 1167–1284.CrossRefGoogle Scholar
  7. 7.
    Cope, E.D., The Primary Factors of Organic Evolution, Chicago, IL: Open Court Publ., 1904.CrossRefGoogle Scholar
  8. 8.
    Depéret, Ch., Les transformations du monde animal, Paris: Flammarion, 1907.Google Scholar
  9. 9.
    Depéret, Ch., Prevrashcheniya zhivotnago mira (Transformations of the Fauna), Borissiak, A., Ed., Petrograd: M. Stasyulevicha, 1915.Google Scholar
  10. 10.
    Klug, C., De Baets, K., Kroger, B., Bell, M.A., Korn, D., and Payne, J.L., Normal giants? Temporal and latitudinal shifts of Palaeozoic marine invertebrate gigantism and global change, Lethaia, 2015, vol. 48, pp. 267–288.CrossRefGoogle Scholar
  11. 11.
    Maslakova, N.I., Gorbachik, T.N., Alekseev, A.S., Barskov, I.S., Golubev, S.N., Nazarov, B.B., and Petrushevskaya, M.G., Mikropaleontologiya: Uchebnik (Micropaleontology: Handbook), Moscow: Mosk. Gos. Univ., 1995.Google Scholar
  12. 12.
    Matsuoka, A., Skeletal growth of a spongiose radiolarian Dictyocoryne truncatum in laboratory culture, Mar. Micropalaeontol., 1992, no. 19, pp. 287–298.Google Scholar
  13. 13.
    Petrushevskaya, M.G., Radiolyarievyi analiz (Radiolarian Analysis), Leningrad: Nauka, 1986.Google Scholar
  14. 14.
    Sander, P.M. and Clauss, M., Sauropod gigantism, Science, 2008, vol. 322, pp. 200–201.CrossRefGoogle Scholar
  15. 15.
    Vermeij, G.J., Gigantism and its implications for the history of life, PLoS ONE, 2016, vol. 11, no. 1, pp. 1–22.CrossRefGoogle Scholar

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© Pleiades Publishing, Ltd. 2018

Authors and Affiliations

  1. 1.Borissiak Paleontological Institute, Russian Academy of SciencesMoscowRussia

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