<p>The work presented here is part of a broader study concerning the biomechanical analysis of the movement of dinosaurs, which will be done by the finite element method (FEM). For this aim, it will be necessary to count on virtual models of the walking system (that is to say, the foot, leg, etc.) and the substrate on which the dinosaur moved. Both kinds of models can be approximately inferred from fossil remains: bones for the former and ichnites (fossil footprints) for the latter. Obviously, there are important challenges in these models, let us see, for example, that a group of fossil bones (probably incomplete and deteriorate) is very far from a walking animal with not only the bones and the articulations but also with flesh, tendons, skin, claws and so on.</p><p> In any case, fossil bones are the only material we have to start modelling. Therefore, the first step will be their 3D digitization. As the expected use of the 3D models defines, the technical characteristics that these models need to comply with, the manuscript will reflect on the qualities that the models for biomechanical purposes need, paying attention to the completeness, geometric accuracy and resolution. Moreover, a practical case is presented with a comparison of a scanning technology (fringe projection) and close range photogrammetry in order to model a 2 meters tall leg of a specimen of Edmontosaurus.</p>