Locomotor habits and bite force influence on cranial sutures complexity in caviomorph rodents

BECERRA, FEDERICO; BUEZAS, GUIDO; ECHEVERRÍA, ALEJANDRA; VASSALLO, ALDO IVÁN

Praga

Congreso; Sociedad de Biología Experimental SEB Praga 2015; 2015

Society of Experimental Biology

As growing sites, cranial sutures are expected to respond to external factors, like thoseresulting from mastication and specialized behaviors (e.g. fighting, aggressive biting,chisel-tooth digging). Higher reaction forces at the incisors? tip and skull would begenerated in those species with greater intensity of use of its masticatory apparatus. Apositive relation between the magnitude of the stress across the sutures and the suturalcomplexity has been proposed previously. Moreover, compressive and tensile stressesare proposed to be related with high and low interdigitation morphologies respectively.Five cranial sutures were studied on 29 species of eight caviomorph rodent families, whichare representative of part of the variability present in the group in terms of body size, dietand ecology. Sutures were photographed, digitally copied, and measured by means oflength ratio (LR) and fractal dimension (FD) indices, in order to analyze whether suturemorphology is influenced by the intensity and/or polarity of stress. Our results indicatedthat the sutures of the rostral region were more complex than neurocranial sutures in allspecies (LR), and species with a higher expected use (e.g. chisel-tooth digging, harderdiet, bite force) of its masticatory apparatus have, in general, more complex sutures (LR).This suggests that suture morphology is influenced by the magnitude of the stress towhich they have been subjected, generated by locomotor habits and/or bite force, allowingthem to absorb greater amounts of energy on species with more demanding requirements.