The Late Devonian (380 to 360 Myr ago) is marked by the apogee of the terrestrialisation process that consists in the establishment of complex continental ecosystems. After the invasion of land by plants, and by arthropods, it is the rise of tetrapods (four-legged vertebrates) at the end of the Devonian that will change Earth’s continental ecosystems forever. Their complete terrestrialisation is only recorded by the Carboniferous and the Late Devonian represents thus the ideal period to understand processes related to tetrapod terrestrialisation. While the taxonomic richness, the phylogenetic relationships and the paleoenvironmental settings of Devonian tetrapods are better understood yet, a serious gap remains in our knowledge of the palaeoecological context. This is a major evolutionary issue, as tetrapods obviously did not evolve in an ecological vacuum and faunal interactions must have been critical driving forces for the transition from water to land. To tackle these issues, the ‘Trophic Networks at the dawn of tetrapod Terrestrialisation’ (TNT) project focuses on the trophic relationships in eight crucial and diverse Devonian vertebrate assemblages containing tetrapods. It blends calcium isotope analyses with statistical analyses of ecomorphological characters to reconstruct the trophic position, trophic interactions, and paleoecology of Late Devonian vertebrates under different environments and climates. Because Recent trophic networks provide a comparative basis for understanding Past ecosystems, two Recent localities, with fossil analogues, are also studied in the scope of the TNT project. The TNT project aims to estimate the predation pressures exerted on tetrapods and if these pressures acted as a driving force for their terrestrialisation.