The crocodilian forearm and wrist: biomechanics and functional morphology

Abstract

An attempt has been made to explain the features of the wrist structure of crocodiles, which sharply distinguish them from other reptiles. Biomechanical model of a crocodilian forearm and manus is created with using of the vector contours method from the theory of mechanisms and machines. The key role of the V finger in the manus stability during the stance phase is shown. On the basis of this data, it is concluded that there is no bipedal stage in evolutionary history of crocodiles and their high specialization for quadrupedal parasagittal running with the emergence of a gallop as a result. The special way of parasagittal forelimb posture of the crocodiles offered to name instant parasagittality.