Meeting Abstract
82.1 Friday, Jan. 7 Mechanical optimization and skull form in New World leaf-nosed bats DUMONT, E.R.*; SAMAVEDAM, K.C.; GROSSE, I.R.; Univ. of Massachusetts at Amherst; Univ. of Massachusetts at Amherst; Univ. of Massachusetts at Amherst bdumont@bio.umass.edu
Links between trophic specialization and skull form are a common theme in comparative studies of mammals. While correlations between form and function are clear and abundant, insights into the mechanisms that may govern them are more elusive. Finite element (FE) analysis recently has emerged as a means of comparing the performance of biological structures in terms of their ability to resist failure (measured as stress) and deformation (measured as strain energy) and the mechanical advantage associated with biting. We explored the link between these performance variables and skull form using New World leaf-nosed bats – arguably the most diverse clade of mammals in terms of both trophic specializations and morphological diversity. We began by using CAD software to construct a geometrically parameterized, 3D surface model of the skull of Carollia perspicillata and meshed it using shell elements. The overall shape of the model closely resembled that of a solid FE model of C. perspicillata constructed from micro-CT scans, and FE analyses of the two models under bilateral canine loading yielded comparable magnitudes and distributions of von Mises stress and comparable mechanical advantage. We then used the parameterized model to evaluate all possible combinations of palate length and width in terms of three performance criteria: von Mises stress, total strain energy and mechanical advantage. We visualized performance within the palate length x width morphospace as response surfaces indicating regions of high and low performance. We then overlaid 83 phyllostomid species on the response surfaces to determine which portions of the morpho-performance space are and are not filled. No species occupy regions of exceptionally high stress or strain energy, suggesting that these parameters may serve as constraints.
