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New approaches to fourier analysis of ammonoid sutures and other complex, open curves

Published online by Cambridge University Press:  08 April 2016

Emily G. Allen*
Affiliation:
Department of Mathematics and Computer Science, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010. E-mail: [email protected]

Abstract

Attempts to use Fourier methods to quantify ammonoid suture shape have failed to yield robust, repeatable results because sutures are complex curves that violate the assumptions of Fourier mathematics. In particular, sampled sutures are artificially truncated such that the first and last sampled points are not equivalent, the folds are non-stationary, and a position along a horizontal reference axis may map to multiple amplitudes along the suture path. Here I introduce an alternative Fourier method—the windowed short-time Fourier transform (STFT)—that accommodates these characteristics of complex curves. For each suture, digitized landmarks were parameterized using a tangent angle function and then smoothed by convolving with an apodization function. Piece-wise Fourier transforms were then calculated and averaged, resulting in a robust, unique quantification of line morphology. STFT coefficients and estimated power spectra describing the relative weights of harmonics were generated for 576 Paleozoic-basal Triassic ammonoid genera, representative of the range of suture morphotypes. While insensitive to major episodes of taxonomic turnover (Frasnian/Famennian, end-Devonian, and Permian/Triassic extinctions), the summed power data support the previously observed trend toward increasing suture complexity through time. Moreover, partitioning the summed power statistic into harmonic ranges allows novel insight into Paleozoic suture evolution. In particular, the data show significant shifts in the dominant morphotypes during periods of rebound and radiation and suggest that basal Triassic ammonoids possessed unique suture morphotypes when compared with those of the Paleozoic.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Aguado, A. S., Nixon, M. S., and Montiel, M. E. 1998. Parameterizing arbitrary shapes via Fourier descriptors for evidence-gathering extraction. Computer Vision and Understanding 69:202221.Google Scholar
Akay, M. 2000. Nonlinear biomedical signal processing: dynamic analysis and modeling. IEE Press, New York.CrossRefGoogle Scholar
Allen, E. G., and Gildner, R. F. 2002. A new Fourier approach to interpreting ammonoid suture morphology. Geological Society of America Abstracts with Programs 24:354.Google Scholar
Anstey, R. L., and Delmet, D. A. 1972. Genetic meaning of zooecial chamber shapes in fossil bryozoans: Fourier analysis. Science 177:10001002.Google Scholar
Anstey, R. L., and Delmet, D. A. 1973. Fourier analysis of zooecial shapes in fossil tubular bryozoans. Geological Society of America Bulletin 84:17531764.2.0.CO;2>CrossRefGoogle Scholar
Bingham, C., Godfrey, M. D., and Tukey, J. W. 1967. Modern techniques of power spectrum estimation. IEEE Transactions on Audio and Electroacoustics AU-15:5665.CrossRefGoogle Scholar
Blackman, R. B., and Tukey, J. W. 1959. The measurement of power spectra, from the point of view of communications engineering. Dover, New York.Google Scholar
Bookstein, F. L., Strauss, R. E., Humphries, J. M., Chernoff, B., Elder, R. L., and Smith, G. R. 1982. A comment upon the uses of Fourier methods in systematics. Systematic Zoology 31:8592.Google Scholar
Boyajian, G., and Lutz, T. 1992. Evolution of biological complexity and its relation to taxonomic longevity in the Ammono-idea. Geology 20:983986.2.3.CO;2>CrossRefGoogle Scholar
Buckland, W. 1836. Geology and mineralogy considered with reference to natural theology. The Bridgewater treatises on the power, wisdom, and goodness of God, as manifested in the creation, Vol. 6. W. Pickering, London Google Scholar
Canfield, D. J., and Anstey, R. L. 1981. Harmonic analysis of cephalopod suture patterns. Mathematical Geology 13:2335.Google Scholar
Crampton, J. S. 1995. Elliptical Fourier shape analysis of fossil bivalves: some practical considerations. Lethaia 28:179186.Google Scholar
Daniel, T. L., Helmuth, B. S., Saunders, W. B., and Ward, P. D. 1997. Septal complexity in ammonoid cephalopods increased mechanical risk and limited depth. Paleobiology 23:470481.Google Scholar
Davis, J. C. 1986. Statistics and data analysis in geology. Wiley, New York.Google Scholar
Dommergues, E., Dommergues, J.-L., Magniez, F., Neige, P., and Verrecchia, E. P. 2003. Geometric measurement analysis versus Fourier series analysis for shape characterization using gastropod shell (Trivia) as an example. Mathematical Geology 35:887894.Google Scholar
Ehrlich, R., Pharr, R. B., and Healy-Williams, N. 1983. Comments on the validity of Fourier descriptors in systematics—a reply. Systematic Zoology 32:202206.Google Scholar
Evans, D. G., Schweitzer, P. N., and Hanna, M. S. 1985. Parametric cubic splines and geological shape descriptions. Mathematical Geology 17:611624.Google Scholar
Foote, M. 1989. Perimeter-based Fourier analysis: a new morphometric method applied to the trilobite cranidium. Journal of Paleontology 63:880885.Google Scholar
Foster, J., and Richards, F. B. 1991. The Gibbs Phenomenon for piecewise-linear approximation. American Mathematical Monthly 98:4748.CrossRefGoogle Scholar
García-Ruiz, J. M., Checa, A., and Rivas, P. 1990. On the origin of ammonite sutures. Paleobiology 16:349354.CrossRefGoogle Scholar
Gibbs, J. W. 1899. Fourier series. Nature 59:200,606.Google Scholar
Gildner, R. F. 2000. A method to quantify and analyze suture patterns. Geological Society of America Abstracts with Programs 32:371.Google Scholar
Gildner, R. F. 2003. A Fourier method to describe and compare suture patterns. Palaeontologia Electronica 6:12 pp.Google Scholar
Gildner, R. F., and Ackerly, S. 1985. A Fourier technique for studying ammonoid sutures. Geological Society of America Abstracts with Programs 17:592.Google Scholar
Harris, F. J. 1978. On the use of windows for harmonic analysis with the discrete Fourier transform. Proceedings of the IEEE 66:5183.Google Scholar
Hassan, M. A., Westermann, G. E. G., Hewitt, R. A., and Dokainish, M. A. 2002. Finite-element analysis of simulated ammonoid septa (extinct Cephalopoda): septal and sutural complexities do not reduce strength. Paleobiology 28:113126.Google Scholar
Hewitt, R. A., and Westermann, G. E. G. 1986. Function of complexly fluted septa in ammonoid shells I. Mechanical principles and functional models. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 172:4769.Google Scholar
Hewitt, R. A., and Westermann, G. E. G. 1987. Function of complexly fluted septa in ammonoid shells II. Septal evolution and conclusions. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 174:135169.Google Scholar
Hewitt, R. A., and Westermann, G. E. G. 1988. Application of buckling equations to the functional morphology of nautiloid and ammonoid phragmacones. Historical Biology 1:231255.CrossRefGoogle Scholar
Hewitt, R. A., and Westermann, G. E. G. 1997. Mechanical significance of ammonoid septa with complex sutures. Lethaia 30:205212.Google Scholar
Jacobs, D. K. 1990. Sutural pattern and shell stress in Baculites with implications for other cephalopod shell morphologies. Paleobiology 16:336348.Google Scholar
Jacobs, D. K. 1992. The support of hydrostatic load in cephalopod shells: adaptive and ontogenetic explanations of shell form and evolution from Hooke 1965 to the present. Evolutionary Biology 26.Google Scholar
Jaecks, G. S., Carlson, S. J., and Sperio, H. J. 2001. Investigating heterochrony in the fossil record: a phylogenetic, biogeo-chemical and morphometric approach. Abstracts with programs, North American Paleontological Convention. Paleobios 21:74.Google Scholar
Kuhl, F. P., and Giardina, C. R. 1982. Elliptical Fourier features of a closed contour. Computer Graphics and Image Processing 18:236258.Google Scholar
Lutz, T. M., and Boyajian, G. E. 1995. Fractal geometry of ammonoid sutures. Paleobiology 21:329342.Google Scholar
MacLeod, N. 1999. Generalizing and extending the eigenshape method of shape space visualization and analysis. Paleobiology 25:107138.Google Scholar
Norton, R. H., and Beer, R. 1976. New apodization functions for Fourier spectroscopy. Journal of the Optical Society of America 66:259264.Google Scholar
Pérez-Claros, J. A., Palmqvist, P., and Olóriz, F. 2002. First and second orders of suture complexity in ammonites: a new methodological approach using fractal analysis. Mathematical Geology 34:323343.Google Scholar
Press, W. H., Teukolsky, S. A., Vetterling, W. T., and Flannery, B. P. 1992. Numerical recipes in C: the art of scientific computing. Cambridge University Press, New York.Google Scholar
Rohlf, F. J. 1990. Fitting curves to outlines. Pp. 167177 in Rohlf, F. J. and Bookstein, F. L., eds. Proceedings of the Michigan morphometrics workshop. University of Michigan Museum of Zoology, Ann Arbor.Google Scholar
Rohlf, F. J. 1998. On the applications of geometric morphometrics to studies of ontogeny and phylogeny. Systematic Biology 47:147158.Google Scholar
Rohlf, F. J., and Archie, J. W. 1984. A comparison of Fourier methods for the description of wing shape in mosquitoes (Diptera: Culcidae). Systematic Zoology 33:302317.Google Scholar
Saunders, W. B. 1995. The ammonoid suture problem: relationships between shell- and septal-thickness and suture complexity in Paleozoic ammonoids. Paleobiology 21:343355.Google Scholar
Saunders, W. B., and Work, D. M. 1996. Shell morphology and suture complexity in Upper Carboniferous ammonoids. Paleobiology 22:189218.CrossRefGoogle Scholar
Saunders, W. B., and Work, D. M. 1997. Evolution of shell morphology and suture complexity in Paleozoic prolecanitids, the rootstock of Mesozoic ammonoids. Paleobiology 23:301325.Google Scholar
Saunders, W. B., Work, D. M., and Nikolaeva, S. V. 1999. Evolution of complexity in Paleozoic ammonoid sutures. Science 286:760763.Google Scholar
Schweitzer, P. N., Kaesler, R. L., and Lohmann, G. P. 1986. Ontogeny and heterochrony in the ostracode Cavellina coryelli from Lower Permian rocks in Kansas. Paleobiology 12:290301.Google Scholar
Smith, G. R. 1990. Homology in morphometrics and phylogenetics. Pp. 325338 in Rohlf, F. J. and Bookstein, F. L., eds. Proceedings of the Michigan morphometrics workshop. University of Michigan Museum of Zoology, Ann Arbor.Google Scholar
Stoica, P., and Moses, R. 1997. Introduction to spectral analysis. Prentice-Hall, Upper Saddle River, N.J. Google Scholar
Tolstov, G. P. 1962. Fourier series. Dover, New York.Google Scholar
Tort, A. 2003. Elliptical Fourier functions as a morphological descriptor of the genus Stenosarina (Brachiopoda, Terebratulida), New Caledonia. Mathematical Geology 35:873885.Google Scholar
Ward, P. D. 1980. Comparative shell shape distributions in Jurassic-Cretaceous ammonites and Jurassic-Tertiary nautiloids. Paleobiology 6:3243.Google Scholar
Welch, P. D. 1967. The use of the fast Fourier transform for the estimation of power spectra: a method based on time averaging over short, modified periodograms. IEEE Transactions on Audio and Electroacoustics 15:7073.Google Scholar
Westermann, G. E. G. 1971. Form, structure and function of shell and siphuncle in coiled Mesozoic ammonoids. Life Science Contributions of the Royal Ontario Museum 78:139.Google Scholar
Westermann, G. E. G. 1975. Model for origin, function, and fabrication of fluted cephalopod septa. Paläontologische Zeitschrift 49:235253.Google Scholar
Younker, J. L., and Ehrlich, R. 1977. Fourier biometrics—harmonic amplitudes as multivariate shape descriptors. Systematic Zoology 3:366–342.Google Scholar
Zahn, C., and Roskies, R. 1972. Fourier descriptors for plane closed curves. IEEE Transactions on Computers C-21:269281.Google Scholar
Zelditch, M. L., Fink, W. L., and Swinderski, D. L. 1995. Morphometrics, homology, and phylogenetics—quantified characters as synapomorphies. Systematic Biology 44:179189.Google Scholar