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Infaunal survival: alternative functions of shell ornamentation in the Bivalvia (Mollusca)

Published online by Cambridge University Press:  08 February 2016

Steven M. Stanley*
Affiliation:
Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218

Extract

Two kinds of adaptation aid infaunal bivalve mollusks in sustaining their life positions against potentially disruptive water movements: (1) ability to retard scour of surrounding sediment and (2) ability to reburrow rapidly if exhumed.

The shell of the venerid Anomalocardia brasiliana is ornamented with concentric ridges that are asymmetrical in cross-section; experiments show that these ridges aid the animal in burrowing by gripping the sediment during backward rotation of the shell. The shell of the less deeply burrowing venerid Chione cancellata also bears concentric ridges, but these are symmetrical and experiments show that they hinder burrowing; other experiments demonstrate that these ridges reduce scour of sand from around a partly exposed animal. The single cardiid species Trachycardium egmontianum possesses adaptations comparable to those of the two venerid species, in the form of spines of two varieties; experiments show that the flared anterior spines facilitate burrowing and the cupped posterior spines reduce scour.

Conspicuous ornamentation of the kinds considered here was rare throughout the Paleozoic. Its evolutionary deployment occurred primarily during the post-Paleozoic adaptive diversification of infaunal bivalves, which was triggered by the evolution of efficient burrowing mechanisms. The general premium on maintaining infaunal life positions was accentuated for bivalves after the Paleozoic by the origins of important modern predatory taxa.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Allen, J. R. L. 1965. Scour marks in snow. J. Sediment. Petrol. 35:331338.Google Scholar
Aller, R. C. 1974. Prefabrication of shell ornamentation in the bivalve Laternula. Lethaia. 7:4356.CrossRefGoogle Scholar
Bottjer, D. J. and Carter, J. G. 1980. Functional and phylogenetic significance of projecting periostracal structures in the Bivalvia (Mollusca). J. Paleontol. 54:200216.Google Scholar
Boyd, D. W. and Newell, N. D. 1968. Hinge grades in the evolution of crassatellacean bivalves as revealed by Permian genera. Am. Mus. Novitates. 2328:151.Google Scholar
Carter, R. M. 1967. The shell ornament of Hysteroconcha and Hecuba (Bivalvia): A test case for inferential functional morphology. Veliger. 10:5971.Google Scholar
Carter, R. M. 1968. On the biology and paleontology of some predators of bivalved Mollusca. Palaeogeogr., Palaeoclimat., Palaeoecol. 4:2965.CrossRefGoogle Scholar
Karcz, I. 1968. Fluviatile obstacle marks from the wadis of the Negev (Southern Israel). J. Sediment. Petrol. 38:10001012.Google Scholar
Kauffman, E. G. 1969. Form, function, and evolution. pp. 129205. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Vol. N. Mollusca 6. Bivalvia. Geol. Soc. Am. and Univ. of Kansas; Lawrence, Kansas.Google Scholar
Lutz, R. A. and Rhoads, D. C. 1977. Anaerobiosis and a theory of growth line formation. Science. 198:12221227.CrossRefGoogle Scholar
Matsukuma, A. 1975. Preliminary report on the effect of the shell shape and asymmetrical ridges of the shell ornamentation on burrowing of infaunal bivalves. Kyushu Univ., College of General Education, Repts. on Earth Science. 19:19.Google Scholar
O'Gower, A. K. and Nicol, P. I. 1971. Orientation of the bivalve Anadara trapezia (Deshayes) relative to water currents. Veliger. 13:275278.Google Scholar
Richardson, P. D. 1968. The generation of scour marks near obstacles. J. Sediment. Petrol. 38:965970.Google Scholar
Seilacher, A. 1972. Divaricate patterns in pelecypod shells. Lethaia. 5:325343.CrossRefGoogle Scholar
Seilacher, A. 1973. Fabricational noise in adaptive morphology. System. Zool. 22:451465.CrossRefGoogle Scholar
Siegel, S. 1956. Nonparametric Statistics for the Behavioral Sciences. McGraw-Hill; New York, N.Y.Google Scholar
Stanley, S. M. 1968. Post-Paleozoic adaptive radiation of infaunal bivalve molluscs—a consequence of mantle fusion and siphon formation. J. Paleontol. 42:214229.Google Scholar
Stanley, S. M. 1969. Bivalve mollusk burrowing aided by discordant shell ornamentation. Science. 166:634635.CrossRefGoogle ScholarPubMed
Stanley, S. M. 1970. Relation of shell form to life habits in the Bivalvia (Mollusca). Geol. Soc. Am. Mem. 125:1296.Google Scholar
Stanley, S. M. 1973. Effects of competition on rates of evolution, with special reference to bivalve molluscs and mammals. System. Zool. 22:486506.CrossRefGoogle Scholar
Stanley, S. M. 1974. What has happened to the articulate brachiopods? Geol. Soc. Am. Abstr. with Progr. 6:966967.Google Scholar
Stanley, S. M. 1975a. Adaptive themes in the evolution of the Bivalvia (Mollusca). Ann. Rev. Earth and Planet. Sci. 3:361385.CrossRefGoogle Scholar
Stanley, S. M. 1975b. Why clams have the shape they have: an experimental analysis of burrowing. Paleobiology. 1:4858.CrossRefGoogle Scholar
Stanley, S. M. 1977. Coadaptation in the Trigoniidae, a remarkable family of burrowing bivalves. Palaeontology. 20:869899.Google Scholar
Stanley, S. M. 1978. Aspects of the adaptive morphology and evolution of the Trigoniidae. Phil. Trans. R. Soc. London (B). 284:247258.Google Scholar
Stanley, S. M. 1979. Macroevolution: Pattern and Process. W. H. Freeman and Co.; San Francisco, California.Google Scholar
Trueman, E. R., Brand, A. R., and Davis, P. 1966. The effect of substrate and shell shape on the burrowing of some common bivalves. Proc. Malac. Soc. London. 37:97109.Google Scholar
Vermeij, G. J. 1977. The Mesozoic marine revolution: evidence from snails, predators, and grazers. Paleobiology. 3:245258.CrossRefGoogle Scholar