In recent years important advances have been accomplished in comparative functional analysis of vertebrate structures. This involved the introduction of virtual models that allowed to test functional hypothesis using Finite Element Analysis (FEA) and its combination with Geometric Morphometrics (GMM) and mathematical, statistical and engineering approaches. The last advances in my research work have been presented at the 89th Annual Meeting of the German Society for Mammalian Biology held in Hannover (Germany) in the work “Comparative methodologies to study the biomechanical traits of the mammal lower jaw using Finite Element Methods” by J. Marcé-Nogué, S. De Esteban-Trivigno, C. Escrig, J. Fortuny, L. Gil, T.M. Kaiser.
FEA enables stress distribution patterns to be obtained by simulating loadings and forces involved. Applied to lower jaws of mammals, it allows comparative approaches to chewing biomechanics under certain loads. Patterns of stress and load response can thus be understood as adaptive to biomechanical diet response. Previously, comparative FEA studies often relied on qualitative evaluation of coded outputs or comparison of load and vector outputs at specific points considered homologous. Still, there is a lack of fully quantitative descriptors to help researchers compare different computational models in order to test hypotheses driven by the biological context.
The aim of this work is to present some new procedures to compare quantitatively FEA results from different models of mammal lower jaws in order to establish a robust methodology in a comparative context. Recommendations are made to be taken into account when building the models (scaling methods, material properties, etc.) as well as pathways of comparison in obtaining isolated points or whole models. Plane models of more than 60 mammals including dietary traits such as insectivory, herbivory, omnivory and carnivory were established using the ANSYS FEA Package v.16 for Windows 7 (64-bit system) in order to obtain the von Mises stress distribution of the planar models and compare them using this new approach.
The results obtained suggest that the proposed methodologies provide powerful indicators that are suitable to be applied in comparative approaches as well as for pattern detection as a proxy system of niche specificities. In particular, the new methods proposed are shown to be extremely useful when exploring the effect that shape has on strength and stiffness of bone structures, such as the lower jaws of the mammals employed as a model here.