Patterns of morphospace occupation and mechanical performance in extant crocodilian skulls: A combined geometric morphometric and finite element modeling approach
Article first published online: 21 MAY 2008
Copyright © 2008 Wiley-Liss, Inc.
Journal of Morphology
Volume 269, Issue 7, pages 840–864, July 2008
How to Cite
Pierce, S. E., Angielczyk, K. D. and Rayfield, E. J. (2008), Patterns of morphospace occupation and mechanical performance in extant crocodilian skulls: A combined geometric morphometric and finite element modeling approach. J. Morphol., 269: 840–864. doi: 10.1002/jmor.10627
- Issue published online: 10 JUN 2008
- Article first published online: 21 MAY 2008
- UK Overseas Scholarship
- University of Bristol Postgraduate Scholarship
- Natural Sciences and Engineering Doctoral Scholarship
- Sir James Lougheed Award of Distinction
- University of Bristol Alumni Association
Extant and fossil crocodilians have long been divided into taxonomic and/or ecological groups based on broad patterns of skull shape, particularly the relative length and width of the snout. However, these patterns have not been quantitatively analyzed in detail, and their biomechanical and functional implications are similarly understudied. Here, we use geometric morphometrics and finite element analysis to explore the patterns of variation in crocodilian skull morphology and the functional implications of those patterns. Our results indicate that skull shape variation in extant crocodiles is much more complex than previously recognized. Differences in snout length and width are the main components of shape variation, but these differences are correlated with changes in other regions of the skull. Additionally, there is considerable disparity within general classes such as longirostrine and brevirostrine forms. For example, Gavialis and Tomistoma occupy different parts of morphospace implying a significant difference in skull shape, despite the fact that both are traditionally considered longirostrine. Skull length and width also strongly influence the mechanical performance of the skull; long and narrow morphotypes (e.g., Tomistoma) experience the highest amount of stress during biting, whereas short and broad morphotypes (e.g., Caiman latirostris) experience the least amount of stress. Biomechanical stress and the hydrodynamic properties of the skull show a strong relationship with the distribution of crocodilians in skull morphospace, whereas phylogeny and biogeography show weak or no correlation. Therefore, ecological specializations related to feeding and foraging likely have the greatest influence on crocodilian skull shape. J. Morphol., 2008. © 2008 Wiley-Liss, Inc.