Hostname: page-component-848d4c4894-4rdrl Total loading time: 0 Render date: 2024-06-15T06:14:45.110Z Has data issue: false hasContentIssue false
  • English
  • Français

Shell form in the biconvex articulate Brachiopoda: a geometric analysis

Published online by Cambridge University Press:  08 February 2016

George R. McGhee Jr.
George R. McGhee Jr.*
Affiliation:
Department of Geological Sciences, Wright Geological Laboratory, Rutgers University, New Brunswick, New Jersey 08903
Get access Rights & Permissions [Opens in a new window]

Abstract

Using a geometric model of shell morphology, it is demonstrated that biconvex brachiopods occupy only a small region of the potential geometric space available to organisms with planispiral exoskeletons composed of two articulated valves. Measurements taken for a sample of 324 genera of the articulate orders Pentamerida, Rhynchonellida, Spiriferida, and Terebratulida were analyzed using a simple geometric model of shell form and ontogeny. The frequency distribution of brachiopod shell morphologies exhibited by the four orders represents the biological optimization of the spatial relationships between area and volume. Biconvex brachiopods develop shells which are designed to minimize shell surface area while maximizing internal shell volume. The means by which optimization is achieved is related directly to the effects of increase in absolute size during ontogeny. The boundaries upon shell geometries utilizable by biconvex brachiopods are determined by (1) limitations of articulation, and (2) limitations of surface and volume.

Type
Articles
Information
Paleobiology , Volume 6 , Issue 1 , Winter 1980 , pp. 57 - 76
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

Alexander, R. R. 1975. Phenotypic lability of the brachiopod Rafinesquina alternata (Ordovician) and its correlation with the sedimentologic regime. J. Paleontol. 49:607–618.Google Scholar
Bayer, U. 1977. Cephalopoden-Septen Teil 2: Regelmechanismen in Gehäuse- und Septenbau der Ammoniten: Konstruktionsmorphologie Nr. 75. N. Jb. Geol. Paläontol. Abh. 155:162–215.Google Scholar
Dobzhansky, Th. 1970. Genetics of the Evolutionary Process. 505 pp. Columbia Univ. Press; New York.Google Scholar
Faber, P., Vogel, K., and Winter, J. 1977. Beziehung zwischen morphologischen Merkmalen der Brachiopoden und Fazies, dargestellt an Beispielen des Mitteldevons der Eifel und Südmarokkos. N. Jb. Geol. Paläontol. Abh. 154:21–60.Google Scholar
Graus, R. R. 1974. Latitudinal trends in the shell characteristics of marine gastropods. Lethaia. 7:303–314.CrossRefGoogle Scholar
McGhee, G. R. Jr. 1978. Analysis of the shell torsion phenomenon in the Bivalvia: Konstruktionsmorphologie Nr. 91. Lethaia. 11:315–329.CrossRefGoogle Scholar
McGhee, G. R. Jr. 1979. Geometric analysis of biconvex brachiopod shell morphology: Ordinal distributions and stability strategies. Geol. Soc. Am. Abstr. 11:44.Google Scholar
Moseley, H. 1838. On the geometrical forms of turbinated and discoid shells. R. Soc. Lond. Philos. Trans, for 1838:351–370.Google Scholar
Raup, D. M. 1966. Geometric analysis of shell coiling: general problems. J. Paleontol. 40:1178–1190.Google Scholar
Raup, D. M. 1967. Geometric analysis of shell coiling: coiling in ammonoids. J. Paleontol. 41:43–65.Google Scholar
Raup, D. M. 1969. Modeling and simulation of morphology by computer. Proc. N. Am. Paleontol. Convent., Part B:71–83.Google Scholar
Raup, D. M. and Michelson, A. 1965. Theoretical morphology of the coiled shell. Science. 147:1294–1295.CrossRefGoogle ScholarPubMed
Raup, D. M. and Chamberlain, J. A. Jr. 1967. Equations for volume and center of gravity in ammonoid shells. J. Paleontol. 41:566–574.Google Scholar
Raup, D. M. and Graus, R. R. 1972. General equations for volume and surface area of a logarithmically coiled shell. Mathemat. Geol. 4:307–316.CrossRefGoogle Scholar
Reif, W.-E. 1975. Lenkende und limitierende Faktoren in der Evolution. Acta Biotheoretica. 24:136–162.CrossRefGoogle ScholarPubMed
Rudwick, M. J. S. 1959. The growth and form of brachiopod shells. Geol. Mag. 96:1–24.CrossRefGoogle Scholar
Rudwick, M. J. S. 1964. The inference of function from structure in fossils. Brit. J. Phil. Sci. 15:27–40.CrossRefGoogle Scholar
Rudwick, M. J. S. 1968. Some analytic methods in the study of ontogeny in fossils with accretionary skeletons. Paleontol. Soc. Mem. 2:35–69.CrossRefGoogle Scholar
rudwick, M. J. S. 1970. Living and Fossil Brachiopods. 199 pp. Hutchinson Univ. Library; London.Google Scholar
Schmidt, H. 1937. Zur Morphologie der Rhynchonelliden. Senckenbergiana. 19:22–60.Google Scholar
Seilacher, A. 1970. Arbeitskonzept zur Konstruktions-morphologie. Lethaia. 3:393–396.CrossRefGoogle Scholar
Thomas, R. D. K. 1979. Constructional morphology. In: Fair-bridge, R. W., ed. The Encyclopedia of Paleontology.Google Scholar
Thompson, D'A. W. 1942. On Growth and Form. 1116 pp. Cambridge Univ. Press; Cambridge.Google Scholar