Form–function relationships determining optimal jumping performance in an early bipedal dinosaur

Abstract Elucidating the optimal movements of extinct animals is crucial for understanding the mechanisms behind evolutionary advantages and adaptations. Here, the vertical jumping performance of the Late Triassic theropod dinosaur Coelophysis bauri is predicted using optimal control simulations and compared with that of the extant generalized bird Eudromia elegans. These simulations predicted similar jumping performances between these species, reflective of their geometrically similar hindlimbs. However, differences in overall body shape and size led to different mechanisms by which these jumps were achieved. The jumping performance of Coelophysis was found to be highly sensitive to changes in the range of motion allowed at the proximal tail joint, and changing the relative mass of the tail also revealed how archosaurs with similar body plans but relatively heavier tails would benefit more from this increased range of motion in terms of jumping performance than those with lighter tails. This study provides important insights into how body size, morphology and joint dynamics may have impacted the ability to jump within morphologically diverse bipedal archosaurs, and thus informs possible hypotheses regarding the evolution of jumping and other high-demand movements within Archosauria.