The function(s) of the bone ornamentation in the crocodylomorph osteoderms: a biomechanical model based on a finite element analysis

This paper aims at assessing the influence of the bone ornamentation and, specifically, of the associated loss of bone mass on the mechanical response of the crocodylomorph osteoderms. To this aim, we have performed three dimensional modeling and finite element analyses on a sample which includes both extant dry bones and well-preserved fossils tracing back to the Late Triassic. We simulated an external attack under variable angles on the apical surface of each osteoderm and further repeated the simulation on an equivalent set of smoothed 3D-modeled osteoderms. The comparative results evidenced that the presence of an apical sculpture has no significant influence on the von Mises stress distribution in the osteoderm volume although it involves a slight increase in its numerical score. Moreover, performing parametric analyses, we evidenced that the Young’s modulus in the osteoderm which may vary depending on the bone porosity, the collagen fiber orientation or the calcification density h...