De la paléohistologie osseuse à l’insularité L’archive paléobiologique comme témoin de l’évolution insulaire

Islands have always fascinated scientists since their extensive exploration and documentation. They were even given the title of ‘natural laboratory’ in view of the replication of evolutionary experiments that they show both by their number and by their simplified condition compared to the mainland. Unfortunately, however idyllic they may appear, islands have suffered from major biodiversity losses due to human activity since the Holocene, disfiguring the evolutionary processes that used to take place locally. Consequently, the study of extinct island species known as ‘paleoinsular’ becomes essential to reconstruct the evolutionary framework characterising these isolated environments. To this end, bone palaeohistology is a tool of choice to access the palaeobiological archives preserved within bone tissue and to reveal the evolutionary trajectories that lead to the appearance of the biological curiosities populating islands. This article takes a particular look at island dwarfs and giants with a case study of dwarf sauropods from the Late Cretaceous European archipelago, in order to provide valuable scientific insights for tracing past worlds, increasing the fields of knowledge of the present, and adopting conservation strategies for the future.