Biting Performance and Skull Biomechanics of a Chisel Tooth Digging Rodent (Ctenomys tuconax; Caviomorpha; Octodontoidea)
Article first published online: 30 NOV 2012
Copyright © 2013 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology
Volume 319, Issue 2, pages 74–85, February 2013
How to Cite
2013. Biting Performance and Skull Biomechanics of a Chisel Tooth Digging Rodent (Ctenomys tuconax; Caviomorpha; Octodontoidea) J. Exp. Zool. 319A:74–85., , .
- Issue published online: 12 FEB 2013
- Article first published online: 30 NOV 2012
- Manuscript Accepted: 8 OCT 2012
- Manuscript Revised: 5 OCT 2012
- Manuscript Received: 12 JUL 2012
- PIP-CONICET. Grant Number: 1380
- ANPCyT PICT. Grant Number: 2121 (2011–2013)
- Ministerio de Ciencia e Innovación de España. Grant Number: CGL2011-23919/BOS (2012–2014)
Biting performance is a key factor in vertebrate groups possessing particular food habits. In subterranean rodents that use the incisors as a digging tool, apart from requirements related to gnawing abrasive diets, the force exerted at the incisors tips must be sufficient to break down soils that are often exceedingly compact. The subterranean genus Ctenomys diversified in the southern portion of South America closely associated with the relatively open environments that characterize that region. This genus is considered a “claw and chisel tooth digger,” that is, during the excavation of their galleries, the animals break down the soil with both the fore-claws and the incisors. We report here measurements of in vivo bite force in one of the largest species of the genus, C. tuconax, which occupies highland grasslands with compacted soils. We document the combined use of claws and incisors observed under field conditions, also providing measurements of soil compaction in the habitat occupied by this species. We report estimates of bite force at the level of the incisors and cheek teeth calculated from the physiological cross-sectional area of jaw muscles. To this aim, anatomical and biomechanical analyses of the mandibular apparatus were performed in preserved specimens. We found that C. tuconax bites with a higher force than expected for a mammal of its size. To assess anatomical correlates of biting performance, the morphology of the skull and jaw, and incisor second moment of area were compared with those of other caviomorph rodents with different lifestyle. J. Exp. Zool. 319A:74–85, 2013. © 2013 Wiley Periodicals, Inc.