FIGURE 1 in The intriguing shapes of the ammonoid whorl

FIGURE 1. Summary of the morphometric and geometric morphometric (GM) models used in this work. A) Cross-section of an ammonoid showing the standard morphometric model to study the ammonoid conch morphology presented by Korn (2010) and Klug et al. (2015). Abbreviations: ah, aperture height; dm, diameter; iz, imprint zone; wh, whorl height, ww, whorl width. B-E) Geometric morphometric model to study the whorl shape presented in Morón-Alfonso et al. (2021). B) Basic virtual model (grey area) showing the corresponding configuration based on 18 semi-landmarks. C) GM model adapted to the specimen shown in A. D) GM model applied to the whorl of an evolute specimen. E) GM model applied to the whorl profile of an involute specimen (modified from Raup 1967).