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Ontogenetic regulatory mechanisms and evolution of mellitid lunules (Echinoidea, Clypeasteroida)

Published online by Cambridge University Press:  08 April 2016

Malcolm Telford
Malcolm Telford*
Affiliation:
Department of Zoology, University of Toronto, Toronto, Ontario M5S 1A1, Canada
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Abstract

Lunules have evolved independently in several groups of clypeasteroids, including the Rotulidae, Astriclypeidae, Mellitidae and Scutasteridae. In this paper, only the monophyletic assemblage Monophorasteridae plus Mellitidae is considered. Lunules result from modifications of the growth patterns of test plates which bring about changes in relative growth in specific directions. It is unnecessary to postulate resorption of the test. Ambulacral lunules, which are known to have hydrodynamic functions, originated as part of a series of changes: 1) bifurcation of food grooves, 2) formation of pressure drainage channels, 3) lobulation of the ambitus (as in Monophoraster), 4) complete lunule formation. The anal lunule shares the hydrodynamic function but arose separately, as a developmental aberration. The position of the periproct is highly variable but it is most commonly located at the junction of suture lines, at plate corners. In Scutella it is located between the first and second post-basicoronal plates. In Monophoraster the periproct is located further forward, between the first post-basicoronal plates, and the small anal lunule occupies the junction point between first and second post-basicoronals. It is hypothesized that the anal lunule originated as an all-or-nothing event following the forward migration of the periproct and failure to resume normal plate growth at the sutural junction point between first and second post-basicoronal plates. Its walls were derived from paired interambulacral supports. The hypothesis is discussed in connection with the ontogenetic formation of the anal lunule in living mellitid sand dollars.

Type
Articles
Information
Paleobiology , Volume 14 , Issue 1 , Winter 1988 , pp. 52 - 63
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Carroll, R. L. 1987. Vertebrate Paleontology and Evolution. W. H. Freeman & Co., San Francisco. 698 pp.Google Scholar
Dafni, J. 1986. A biomechanical model for the morphogenesis of regular echinoid tests. Paleobiology 12:143–160.Google Scholar
Durham, J. W. 1966. Clypeasteroids. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology. Pt. U. Echinodermata. Geological Society of America and University of Kansas Press. 695 pp.Google Scholar
Durham, J. W. 1953. Type species of Scutella. Journal of Paleontology 27:347–352.Google Scholar
Ellers, O. and Telford, M. 1984. Collection of food by oral surface podia in the sand dollar, Echinarachnius parma (Lamarck). Biological Bulletin 166:574–585.Google Scholar
Goodbody, I. 1960. The feeding mechanism in the sand dollar, Mellita sexiesperforata (Leske). Biological Bulletin 119:80–86.Google Scholar
Gould, S. J. 1984. Morphological channeling by structural constraint: convergence in styles of dwarfing and gigantism in Ccrion, with a description of two new fossil species and a report on the discovery of the largest Cerion. Paleobiology 10:172–194.CrossRefGoogle Scholar
Gould, S. J. and Lewontin, R. C. 1979. The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proceedings of the Royal Society of London B. 205:581–598.Google Scholar
Gould, S. J. and Vrba, E. S. 1982. Exaptation—a missing term in the science of form. Paleobiology 8:4–15.Google Scholar
Hyman, L. H. 1955. The Invertebrates. IV. Echinodermata. McGraw-Hill Inc., New York. 763 pp.Google Scholar
Kier, P. M. 1963. Tertiary echinoids from the Caloosahatchee and Tamiami formations of Florida. Smithsonian Miscellaneous Collections 145:1–63.Google Scholar
Lane, J. M. and Lawrence, J. M. 1982. Food, feeding and absorption efficiencies of the sand dollar, Mellita quinquiesperforata (Leske). Estuarine Coastal Shelf Science 14:421–431.Google Scholar
Maynard Smith, J., Burian, R., Kauffman, S., Alberch, P., Campbell, J., Goodwin, B., Lande, R., Raup, D., and Wolpert, L. 1985. Developmental constraints and evolution. Quarterly Review of Biology 60:265–287.Google Scholar
McNamara, K. J. In press. Heterochrony and the evolution of echinoids. In Smith, A. B. (ed.), Echinoderm Phylogeny.Google Scholar
Mooi, R. 1986. Non-respiratory podia of clypeasteroids (Echinodermata, Echinoides): II. Diversity. Zoomorphology 106:75–90.Google Scholar
Mooi, R. 1987. A cladistic analysis of the sand dollars (Clypeasteroida: Scutellina) and the interpretation of heterochronic phenomena. Ph.D. Dissertation, Department of Zoology, University of Toronto. 204 pp.Google Scholar
Raff, R. A., Anstrom, J. A., Huffman, C. J., Leaf, D. S., Loo, J.-H., Showman, R. M., and Wells, D. E. 1984. Origin of a gene regulatory mechanism in the evolution of echinoderms. Nature 310:312–314.Google Scholar
Raff, R. A. and Kaufman, T. C. 1983. Embryos, Genes and Evolution. Macmillan, New York. 395 pp.Google Scholar
Raup, D. M. 1968. Theoretical morphology of echinoid growth. Journal of Paleontology 42:50–63.Google Scholar
Seilacher, A. 1979. Constructional morphology of sand dollars. Paleobiology 5:191–221.Google Scholar
Smith, A. B. 1984. Echinoid Palaeobiology. George Allen and Unwin, London. 190 pp.Google Scholar
Telford, M. 1984. An experimental analysis of lunule function in the sand dollar, Mellita quinquiesperforata. Marine Biology 76:125–134.Google Scholar
Telford, M. 1981. A hydrodynamic interpretation of sand dollar morphology. Bulletin of Marine Science 31:605–622.Google Scholar
Telford, M., Harold, A. S., and Mooi, R. 1983. Feeding structures, behavior and microhabitat of Echinocyamus pusillus (Echinoidea: Clypeasteroida). Biological Bulletin 151:745–757.Google Scholar
Telford, M. and Mooi, R. 1986. Resource partitioning by sand dollars in carbonate and siliceous sediments: evidence from podial and particle dimensions. Biological Bulletin 171:197–207.Google Scholar
Telford, M., Mooi, R., and Ellers, O. 1985. A new model of podial deposit feeding in the sand dollar, Mellita quinquiesperforata (Leske): the sieve hypothesis challenged. Biological Bulletin 169:431–448.Google Scholar
Telford, M., Mooi, R., and Harold, A. S. 1987. Feeding activities of two species of Clypeaster (Echinoides, Clypeasteroida): Further evidence of clypeasteroid resource partitioning. Biological Bulletin 172:324–336.Google Scholar
Young, J. Z. 1950. The Life of Vertebrates. Oxford University Press, London. 767 pp.Google Scholar