Comparative cranial biomechanics in two lizard species: impact of variation in cranial design

Autor: Susan E. Evans, Anthony Herrel, Peter J. Watson, Hugo Dutel, Callum F. Ross, Marc E. H. Jones, Michael J. Fagan, Flora Gröning, Alana C. Sharp
Přispěvatelé: School of Earth Sciences [Bristol], University of Bristol [Bristol], University of Hull [United Kingdom], University of Aberdeen, University of Liverpool, Mécanismes Adaptatifs et Evolution (MECADEV), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), University of Chicago, University College of London [London] (UCL)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Dutel, H, Gröning, F, Sharp, A C, Watson, P J, Herrel, A, Ross, C F, Jones, M E H, Evans, S E & Fagan, M J 2021, ' Comparative cranial biomechanics in two lizard species: impact of variation in cranial design ', The Journal of Experimental Biology, vol. 224, no. 5, jeb234831 . https://doi.org/10.1242/jeb.234831
Journal of Experimental Biology
Journal of Experimental Biology, The Company of Biologists, 2021, 224 (5), pp.234831. ⟨10.1242/jeb.234831⟩
The Journal of Experimental Biology
article-version (VoR) Version of Record
ISSN: 0022-0949
1477-9145
DOI: 10.1242/jeb.234831
Popis: Cranial morphology in lepidosaurs is highly disparate and characterised by the frequent loss or reduction of bony elements. In varanids and geckos, the loss of the postorbital bar is associated with changes in skull shape, but the mechanical principles underlying this variation remain poorly understood. Here, we sought to determine how the overall cranial architecture and the presence of the postorbital bar relate to the loading and deformation of the cranial bones during biting in lepidosaurs. Using computer-based simulation techniques, we compared cranial biomechanics in the varanid Varanus niloticus and the teiid Salvator merianae, two large, active foragers. The overall strain magnitude and distribution across the cranium were similar in the two species, despite lower strain gradients in V. niloticus. In S. merianae, the postorbital bar is important for resistance of the cranium to feeding loads. The postorbital ligament, which in varanids partially replaces the postorbital bar, does not affect bone strain. Our results suggest that the reduction of the postorbital bar impaired neither biting performance nor the structural resistance of the cranium to feeding loads in V. niloticus. Differences in bone strain between the two species might reflect demands imposed by feeding and non-feeding functions on cranial shape. Beyond variation in cranial bone strain related to species-specific morphological differences, our results reveal that similar mechanical behaviour is shared by lizards with distinct cranial shapes. Contrary to the situation in mammals, the morphology of the circumorbital region, calvaria and palate appears to be important for withstanding high feeding loads in these lizards.
Summary: In vivo measurements and computer-based simulations of the cranial mechanics of two large lizards indicate that similar mechanical behaviour is shared by lizards with distinct cranial architecture, and show the importance of the postorbital bar in resisting the feeding loads.
Databáze: OpenAIRE
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