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Shell sculpture as a defensive adaptation in ammonoids

Published online by Cambridge University Press:  08 February 2016

Peter Ward
Peter Ward*
Affiliation:
Department of Geology, University of California, Davis, California, 95616
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Extract

Quantification of Paleozoic, Triassic, Jurassic, and Cretaceous ammonoid shell ornamentation shows that commonality and roughness of ornamentation increased throughout the geologic range of the ammonoids. The two major hypotheses concerning the function of ammonoid shell ornamentation are that 1) ornament served a protective (defensive) function against shell breakage by predators, and 2) it increased hydrodynamic efficiency of the shell during swimming. The heavily ribbed and spined ammonoid shells of the late Mesozoic have ornamentation too coarse to have served any hydrodynamic purpose. The increasing proportion of such shells during the Jurassic and Cretaceous may have been in response to increased numbers of late Mesozoic shell crushing predators and “better armed” ammonoid prey. This trend parallels adaptive trends of other invertebrate groups during the “Mesozoic marine revolution” as defined by Vermeij (1977).

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Articles
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Paleobiology , Volume 7 , Issue 1 , Winter 1981, pp. 96 - 100
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Chamberlain, J. and Westermann, G. 1976. Hydrodynamic properties of cephalopod shell ornament. Paleobiology. 2: 316–331.CrossRefGoogle Scholar
Cowen, R., Gertman, R., and Wiggett, G. 1973. Camouflage patterns in Nautilus, and their implications for cephalopod paleobiology. Lethaia. 6: 201–213.CrossRefGoogle Scholar
Currey, J. and Kohn, A. 1976. Fracture in the crossed-lamellar structure of Conus shells. J. Materials Sci. 11: 1615–1623.CrossRefGoogle Scholar
Kanie, Y., Tanabe, K., Fukuda, Y., Hirano, H., and Obata, I. 1978. Preliminary study of jaw apparatus in some late Cretaceous ammonites from Japan and Sakhalin. J. Geol. Soc. Japan. 84: 629–631.CrossRefGoogle Scholar
Kauffman, E. and Kesling, R. 1960. An Upper Cretaceous ammonite bitten by a mosasaur. Univ. Mich. Contrib. Mus. Paleontol. 15: 193–248.Google Scholar
Kennedy, W. and Cobban, W. 1976. Aspects of ammonite biology, biogeography, and biostratigraphy. Spec. Pap. in Palaeontol., no. 17. 94 pp.Google Scholar
Lehmann, U. 1976. Ammoniten, ihr Leben und ihre Umwelt. Enke Verlag, Stuttgart. 171 pp.Google Scholar
Roll, A. 1935. Uber Frasspuren an Ammonitenschalen. Zbl. Miner. Geol. Palantol. Abt. 13: 120–124.Google Scholar
Spath, L. 1919. Notes on ammonites. Geol. Mag. 56: 27–35.CrossRefGoogle Scholar
Teichert, C. 1967. Major features of cephalopod evolution. pp. 162–201. In: Teichert, C. and Yochelson, E., eds. Essays in Paleontology and Stratigraphy. Univ. Kansas Press, Spec. Publ. 2.Google Scholar
Thiermann, A. 1964. Uber verheilte Verletzungen an zwei kretazischen Ammonitengehausen. Fortschr. Geol. Rheinld. Westf. 7: 27–30.Google Scholar
Vermeij, G. 1977. The Mesozoic marine revolution: evidence from snails, predators and grazers. Paleobiology. 3: 245–258.CrossRefGoogle Scholar
Ward, P. and Wicksten, M. 1980. Food sources and feeding behavior of Nautilus macromphalus. Veliger. 23: 119–124.Google Scholar
Westermann, G. 1971. Form, structure and function of shell and siphuncle in coiled Mesozoic ammonoids. Life Sciences Contributions, R. Ontario Mus., no. 78. 39 pp.CrossRefGoogle Scholar