Wavelet analysis of ammonoid sutures

Abstract

A morphometric method based on a continuous wavelet transform is introduced for describing the form of ammonoid suture lines. A series of y-coordinate data along the suture line placed in a common reference system was used as the descriptor function of the cumulative chordal length along the suture line. The wavelet transform is defined as an inner product between the descriptor function and a finite-length localized waveform, termed a "daughter wavelet." The absolute values of wavelet transforms, or amplitudes, were computed for individual daughter wavelets with various wavelengths and positions, and a series of amplitudes for different frequencies was used as a shape function in characterizing the suture shape and was summarized into a few principal components. © Paleontological Society February 2014.