Evolutionary biomechanics: hard tissues and soft evidence?

Biomechanical modelling is a powerful tool for quantifying the evolution of functional performance in extinct animals to understand key anatomical innovations and selective pressures driving major evolutionary radiations. However, fossil record composed predominantly hard parts, forcing palaeontologists reconstruct soft tissue properties such models. Rarely are these reconstruction approaches validated on extant animals, despite being highly determinant performance. The extent which reconstructions biomechanical models accurately predict quantitative or even qualitative patterns macroevolutionary studies therefore unknown. Here, we modelled masticatory system rodents objectively test ability current muscle methods correctly identify differences between morphotypes. Baseline generated using measured yielded proportions, bite force, bone stress expected sciuromorph, myomorph, hystricomorph rodents. predictions from typically used varied widely high levels accuracy failure capture relative Our novel experiment emphasizes that reconstructing taxa radiation challenging methods. Future should incorporate systematic assessments error into their hypothesis testing and, moreover, seek expand primary datasets better inform studies.