Masticatory system integration in a commensal canid: interrelationships between bones, muscles, and bite force in the red fox [RESEARCH ARTICLE]

Colline Brassard, Marilaine Merlin, Elodie Monchatre-Leroy, Claude Guintard, Jacques Barrat, Helene Gares, Arnaud Larralle, Raymond Triquet, Celine Houssin, Cecile Callou, Raphaël Cornette, and Anthony Herrel The jaw system in canids is essential for defence and prey acquisition. However, how it varies in wild species in comparison with domestic species remains poorly understood, yet is of interest to understand the impact of artificial selection. Here we explore the variability and interrelationships between the upper and lower jaws, muscle architecture, and bite force in the red fox (Vulpes vulpes). We performed dissections and used 3D geometric morphometric approaches to quantify shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of ten silver foxes. Our results show strong relationships exist between the cranium and mandible and the cranium or mandible on the one hand and muscles or estimated bite force on the other hand confirming the strong integration of the bony and muscular components of the jaw system. These strong relationships are strongly driven by size. The functional links between shape and estimated bite force are stronger for the mandible, which likely reflects its greater specialisation towards biting.We then compared our results with data previously obtained for dogs (Canis familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiologica...

Source: Journal of Experimental Biology - February 22, 2021 Category: Biology Authors: Brassard, C., Merlin, M., Monchatre-Leroy, E., Guintard, C., Barrat, J., Gares, H., Larralle, A., Triquet, R., Houssin, C., Callou, C., Cornette, R., Herrel, A. Tags: RESEARCH ARTICLE Source Type: research