Publications in the series 'Guides sur la diversite biologique de Madagascar' serve several important purposes: To allow the dissemination of information, particularly in this case knowledge on the Malagasy biota; To allow Malagasy researchers to participate in an international forum of information exchange and the advancement of science; As an important step in the capacity building of emerging young Malagasy biologists. In French. Using scientific evidence from 13 different paleontological and archaeological sites, the authors have reviewed recent geological on ecological changes that have occurred over time, and their impact on habitats, plants, and animals.