How sauropod dinosaurs were able to withstand the forces associated with their immense size represents one of the most challenging biomechanical scenarios in the evolution of terrestrial tetrapods, but also one lacking robust biomechanical testing. Here, we use finite element analyses to quantify the biomechanical effects of foot skeletal postures with and without the presence of a soft tissue pad in sauropodomorphs. We find that none of the models can maintain bone stresses that fall within optimal bone safety factors in the absence of a soft tissue pad. Our findings suggest that a soft tissue pad in sauropods would have reduced bone stresses by combining the mechanical advantages of a functionally plantigrade foot and the plesiomorphic digitigrade saurischians conditions. The acquisition of a developed soft tissue pad by the Late-Triassic–Early-Jurassic may represent one of the key adaptations for the evolution of gigantism that has become emblematic of these dinosaurs.

The raw dataset was collected in international museum collection. 3D models were reconstructed via photogrammetry using Agisoft Photoscan Professional v1.0.3 . 3D models were edited into Autodesk Maya 2017 (www.autodesk.com). Each 3D surface model was then cleaned and converted into a volumetric mesh file of continuum linear tetrahedral elements of types C3D4 using 3-Matic 11.0 software (Materialize Inc., Leuven, Belgium). Finally, each mesh file was then imported into Abaqus/CAE 6.13-6.23 FEA software where the full set of analysis was performed.

All *.inp files may initially be opened with any text editors and into Abaqus/CAE FEA software for further analysis to be undertaken. Note: a valid license of Abaqus would be required to open the *.odb files as the number of node of all of our model exceed the free viewer of 1000 nodes. The *.inp files include the full set of postural morphotype for each specimen. The FEA results for each of our analysis presented in our main text. A detailed explanation of the file extension is provided in the README.txt file.