Skip to main content

Research Repository

Advanced Search

In vivo cranial bone strain and bite force in the agamid lizard Uromastyx geyri

Porro, L. B.; Ross, C. F.; Iriarte-Diaz, J.; O'Reilly, J. C.; Evans, S. E.; Fagan, M. J.


L. B. Porro

C. F. Ross

J. Iriarte-Diaz

J. C. O'Reilly

S. E. Evans

M. J. Fagan


In vivo bone strain data are the most direct evidence of deformation and strain regimes in the vertebrate cranium during feeding and can provide important insights into skull morphology. Strain data have been collected during feeding across a wide range of mammals; in contrast, in vivo cranial bone strain data have been collected from few sauropsid taxa. Here we present bone strain data recorded from the jugal of the herbivorous agamid lizard Uromastyx geyri along with simultaneously recorded bite force. Principal and shear strain magnitudes in Uromastyx geyri were lower than cranial bone strains recorded in Alligator mississippiensis, but higher than those reported from herbivorous mammals. Our results suggest that variations in principal strain orientations in the facial skeleton are largely due to differences in feeding behavior and bite location, whereas food type has little impact on strain orientations. Furthermore, mean principal strain orientations differ between male and female Uromastyx during feeding, potentially because of sexual dimorphism in skull morphology.


Porro, L. B., Ross, C. F., Iriarte-Diaz, J., O'Reilly, J. C., Evans, S. E., & Fagan, M. J. (2014). In vivo cranial bone strain and bite force in the agamid lizard Uromastyx geyri. The journal of experimental biology, 217(11), 1983-1992.

Journal Article Type Article
Acceptance Date Feb 8, 2014
Online Publication Date May 28, 2014
Publication Date Jun 1, 2014
Deposit Date May 26, 2015
Publicly Available Date Oct 27, 2022
Journal Journal of experimental biology
Print ISSN 0022-0949
Electronic ISSN 1477-9145
Publisher The Company of Biologists
Peer Reviewed Peer Reviewed
Volume 217
Issue 11
Pages 1983-1992
Keywords Feeding, Skull, Biomechanics, Squamates
Public URL
Publisher URL
Additional Information Copy of an article published in the Journal of experimental biology, 2014, v.217 at


Article (1.2 Mb)

Publisher Licence URL

Copyright Statement
© 2014. Published by The Company of Biologists Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.

You might also like

Downloadable Citations