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

BECERRA FEDERICO; BUEZAS GUIDO NICOLÁS; ECHEVERRÍA ALEJANDRA ISABEL; VASSALLO ALDO IVÁN

Praga

Congreso; 2015 Annual Main Meeting of the Society for Experimental Biology; 2015

Society for Experimental Biology

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