Skip to main content
SpringerLink
Log in

Model for origin, function and fabrication of fluted cephalopod septa

  • Published:
Paläontologische Zeitschrift Aims and scope Submit manuscript

Abstract

The model supposes that sub-hemispheric septa of deep-water cephalopods evolved transverse pillars by meridional fluting in order to support flat and therefore weak areas of the shell wall. Several trends toward reduction of sutural spacing for improved wall support resulted in rise of fluting and finally, marginal crenulation. During ontogeny, the function of the ammonite septum as complex vault system against ”normal“ pressure from the body was succeeded by compound-pillar function for wall support. Fabrication of ammonitic septa probably involved positive pressure differential of new ”cameral“ liquid, orientation of mantle fibers along stress lines, and successively affixed tie-points which lay on an aponeurosislike mantle structure.

Zusammenfassung

Das Modell nimmt an, daß subhemisphärische Septen von Tiefsee-Cephalopoden phylogenetisch transversale Pfeiler durch meridionale »Faltung« (fluting) entwickelten, um flache und daher schwache Teile der Schalenwand zu unterstützen. Mehrere Trends zur Verminderung des Suturabstandes für verbesserte Wandabstützungen resultieren in vergrößerter Faltungshöhe und schließlich randlicher Krenulierung des Septums. Das ammonitisene Septum funktionierte ontogenetisch zuerst als komplexes Gewölbe gegen Körperdruck, dann ais Bündelpfeiler für Wandabstützung. Die Fabrizierung des Ammonitenseptums wurde wahrscheinlich durch positiven Druckunterschied der neuen Kammerflüssigkeit, Ausrichtung der Mantelfasern nach den Drucklinien und nacheinander befestigte Haftpunkte entlang einer Aponeurosis-ähnlichen Mantel-Struktur unterstützt.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Currey, J. D. &Taylor, J. D. (1974): The mechanical behaviour of some molluscan hard tissues. — J. Zool. (London),173: 395–406.

    Google Scholar 

  • Erben, H. K. (1964a): Die Evolution der ältesten Ammonoidea (Lieferung I). — N. Jb. Geol. Paläont., Abh.120: 107–212.

    Google Scholar 

  • Erben, H. K. (1964b): Bactritoidea. — [In:] Treatise of Invertebrate Paleontology,R. C. Moore, Ed., Part K, Mollusca 3, K 491—K 505. Geol. Soc. Amer, and Univ. Kansas Press.

  • Gould, S.J. (1970): Evolutionary paleontology and the science of form. — Earth Science Rev.,6: 77–119.

    Article  Google Scholar 

  • Gregoire, Ch. (1967): Sur la structure des matrices organiques des coquilles des mollusques. — Biol. Rev.,42: 653–688.

    Article  Google Scholar 

  • Hillebrandt, M. (1974): Analysis of vertebrate structure. — J.Wiley & Sons, Toronto.Jordan, R. (1968): Zur Anatomie mesozoischer Ammoniten nach den Strukmrelementen der Gehäuse-Innenwand. — Beih. Geol. Jb.,77: 1–64, pl. 1—10.

    Google Scholar 

  • Mutvei, H. &Reyment, R. A. (1973): Buoyancy control and siphuncle function in ammonoids. — Palaeontology,16: 623–636.

    Google Scholar 

  • Newell, N. D. (1949): Phyletic size increase, an important trend illustrated by fossil invertebrates. — Evolution,3: 103–124.

    Article  Google Scholar 

  • Pfaff, E. (1911): über Form und Bau der Ammonitensepten und ihre Beziehungen zur Suturlinie. — Jber. niedersächs. geol. Ver. Hannover (Geol. Abt. Naturhist. Ges. Hannover),4: 207–223.

    Google Scholar 

  • Raup, D. M. (1972): Approaches to morphologic analysis. — [In:] Models in Paleobiology,T. J. M. Schopf, Ed., 28–44. Freeman, Cooper & Co., San Francisco.

    Google Scholar 

  • Rudwick, M. J. S. (1964): The inference of function from structure in fossils. — Brit. J. Phil. Sci.,15: 27–40.

    Article  Google Scholar 

  • —— (1970): Living and fossil brachiopods. — [In:] Biol. Scis.,A. J. Cain, Ed., 199 p. Hutchinson Univ. Libr., London.

    Google Scholar 

  • Schmidt, M. (1925): Ammonitenstudien. — Fortschr. Geol. Paläont.,10, I—IV: 275–363.

    Google Scholar 

  • Seilacher, A. (1970): Arbeitskonzept zur Konstruktionsmorphologie. — Lethaia,3: 393–396.

    Article  Google Scholar 

  • —— (1974): Fabricational noise in adaptive morphology. — System. Zool.,22: 451–461.

    Article  Google Scholar 

  • Spath, C. F. (1919): Notes on ammonites. — Geol. Mag.,56: 27–35, 65—74, 115—122, 170 bis 177, 220—225.

    Google Scholar 

  • Stenzel, H. B. (1964): Living Nautilus. — [In:] Treatise on Invertebrate Paleontology,R. C. Moore, Ed., K, Molluska 3, K 59—93.

  • Swinnerton, H. H. (1918): The morphology and development of the ammonite septum. — Geol. Soc. London, Quart. J.,73: 26–57.

    Article  Google Scholar 

  • Taylor, J. D. &Layman, M. (1972): The mechanical properties of bivalve (Mollusca) shell structures. — Palaeontology,15: 73–87.

    Google Scholar 

  • Thompson, d’A. W. (1942): On growth and form. — 1116 p. Cambridge Univ. Press and Macmillan Co.

  • Westermann, G. E. G. (1956): Phylogenie der Stephanocerataceae und Perisphinctaceae des Dogger. — N. Jb. Geol. Paläont. Abh.103: 233–279.

    Google Scholar 

  • —— (1958): The significance of septa and sutures in Jurassic ammonite systematics. — Geol. Mag.,95: 441–455.

    Article  Google Scholar 

  • —— (1965): Septal and sutural patterns in evolution and taxonomy of Thamboceratidae and Clydoniceratidae (M. Jurassic, Ammonitina). — J. Paleont.,39: 864–874.

    Google Scholar 

  • —— (1971): Form, structure and function of shell and siphuncle in coiled Mesozoic amraonoids. — Royal Ontario Museum, Life Sci. Contr.,78: 1–39. Toronto.

    Google Scholar 

  • —— (1972): The case of alleged inversion of septal sutures in ammonites. — Lethaia5: 165–167.

    Article  Google Scholar 

  • —— (1972) Strength of concave septa and depth limits of fossil cephalopods. — Lethaia,6: 383 bis 403.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Geology, McMaster University, L8S 4ML, Hamilton, Ontario, Canada

    G. E. G. Westermann

Authors
  1. G. E. G. Westermann
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Westermann, G.E.G. Model for origin, function and fabrication of fluted cephalopod septa. Paläontol. Z. 49, 235–253 (1975). https://doi.org/10.1007/BF02987661

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02987661

Keywords

Search

Navigation