Modelling compressive loading in large‐bodied mammals reveals distinct biomechanical strategies in proboscidean humeri

Proboscideans exhibit limb morphologies specialised for supporting extreme bodymasses under predominantly compressive loading. These graviportal adaptationsinclude repositioning of the limb bones closer to the trunk, resulting in a columnarstance. Among proboscideans, two humeral morphotypes have been proposed(slender and robust), yet their functional significance under compressive loadingremains poorly understood. Finite element analysis (FEA) is applied to evaluatebiomechanical performances of proboscidean humeri subject to axial compression,simulating conditions associated with a columnar stance and deviations from it.Our results reveal clear differences between morphotypes, with slender humeriperforming worse than the robust morphotype and functioning optimally undernear-axial loading. Robust humeri consistently exhibit lower peak stress underboth neutral and off-axis loading and show considerable resistance to mediolateralstresses. Across all taxa, stress magnitudes generally increase when deviating from aneutral orientation, especially during posterior loading orientations, highlighting themechanical importance of maintaining columnar limb posture. These findings supportthe hypothesis that robust morphologies are better adapted to resist multidirectionalstresses, while slender morphologies favour energetic and locomotor efficiency. Thisstudy demonstrates the applicability of FEA in assessing compressive performance inpostcranial elements and provides a novel framework for investigating biomechanicaladaptations in graviportal taxa