Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-18T17:16:42.876Z Has data issue: false hasContentIssue false
  • English
  • Français

Septum morphology and bathymetry in cephalopods

Published online by Cambridge University Press:  08 February 2016

Gerd E. G. Westermann  and
Peter Ward
Gerd E. G. Westermann
Affiliation:
Department of Geology, McMaster University, Hamilton, Ontario L8S 4M1
Peter Ward
Affiliation:
Geology Department, University of California, Davis, California 95616
Get access Rights & Permissions [Opens in a new window]

Abstract

Nautilus pompilius at Fiji lives abundantly to about 600 m depth while the shell implodes between 730–900 m when sunk in a cage. From this, and the average parameters of the septum, its tensile strength is calculated to 110–140 MPa. This is markedly higher than the latest value from direct tensile tests (78 MPa). In recent pressure tests by Saunders and Wehman with dry shells from the Philippines, implosion occurred at pressure equivalents to 310–680 m depth, without significant correlation with septal thickness. We attribute this excessive range and non-correlation to structural damage by postnecrotic processes. The recalculated tensile strength from their original data is 56–137 MPa; the higher values are compatible with our values for septal nacre of Nautilus and Spirula (c. 155 MPa). Septal curvature and thickness in orthocones thus remain useful guides to bathymetry.

Type
Articles
Information
Paleobiology , Volume 6 , Issue 1 , Winter 1980 , pp. 48 - 50
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Currey, J. D. 1976. Further studies on the mechanical properties of mollusc shell material. J. Zool., London. 180:445–453.CrossRefGoogle Scholar
Currey, J. D. and Taylor, T. D. 1974. The mechanical behavior of some molluscan hard tissues. J. Zool., London. 173:395–406.CrossRefGoogle Scholar
Denton, E. J. and Gilpin-Brown, J. B. 1973. Flotation mechanisms in modern and fossil cephalopods. Adv. Mar. Biol. 11:197–268.CrossRefGoogle Scholar
Saunders, W. B. and Wehman, D. A. 1977. Shell strength of Nautilus as a depth limiting factor. Paleobiology. 3:83–89.CrossRefGoogle Scholar
Ward, P. and Martin, A. 1980. Depth distributions of Nautilus pompilius in Fiji and N. macromphalus in New Caledonia. Veliger. 22:259–264.Google Scholar
Ward, P., Greenwald, L. and Rougerie, F. 1980. Shell implosion depth for living Nautilus macromphalus and implications for shell strength of extinct chambered cephalopods. Lethaia. In Press.CrossRefGoogle Scholar
Westermann, G. E. G. 1973. Strength of concave septa and depth limits of fossil cephalopods. Lethaia. 6:383–403.CrossRefGoogle Scholar
Westermann, G. E. G. 1977. Form and function of orthoconic cephalopod shells with concave septa. Paleobiology. 3:300–321.CrossRefGoogle Scholar