My PhD subject is dealing with major crises and their impact on marine vertebrates communities using geochemical and morphological proxies. This project aims to characterize changes in trophic relationship around Devonian/Carboniferous and Cretaceous/Paleogene crises using dental material of marine vertebrates that is abundant in the fossil record of the two sites that I am working on: The Montagne Noire area (south France) and the phosphates deposits of Morocco.