The Impact of Digging on Craniodental Morphology and Integration

Andrew McIntosh, Philip Graham Cox

Research output: Contribution to journalArticlepeer-review


The relationship between the form and function of the skull has been the subject of a great deal of research, much of which has concentrated on the impact of feeding on skull shape. However, there are a number of other behaviours that can influence craniodental morphology. Previous work has shown that subterranean rodents that use their incisors to dig (chisel-tooth digging) have a constrained cranial shape, which is probably driven by a necessity to create high bite forces at wide gapes. Chisel-tooth-digging rodents also have an upper incisor root that is displaced further back into the cranium compared with other rodents. This study quantified cranial shape and upper incisors of a phylogenetically diverse sample of rodents to determine if chisel-tooth-digging rodents differ in craniodental morphology. The study showed that the crania of chisel-tooth-digging rodents shared a similar place in morphospace, but a strong phylogenetic signal within the sample meant that this grouping was nonsignificant. It was also found that the curvature of the upper incisor in chisel-tooth diggers was significantly larger than in other rodents. Interestingly, most subterranean rodents in the sample (both chisel-tooth and scratch diggers) had upper incisors that were better able to resist bending than those of terrestrial rodents, presumably due to their similar diets of tough plant materials. Finally, the incisor variables and cranial shape were not found to covary consistently in this sample, highlighting the complex relationship between a species’ evolutionary history and functional morphology.

Original languageEnglish
Pages (from-to)2383-2394
Number of pages12
JournalJournal of evolutionary biology
Issue number12
Early online date13 Aug 2016
Publication statusPublished - 8 Dec 2016

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© John Wiley, 2016. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. Embargo period: 12 months.


  • cranial evolution
  • geometric morphometrics
  • phylogenetic comparative methods
  • subterranean rodents

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