After more than two centuries of scientific studies, fossils still have a lot of secrets to reveal. In many cases, external morphological investigations are insufficient. Both external and internal anatomical characters have to be taken into account in order to fully understand a fossil organism. Moreover, different scales of study have to be used, from the histological aspect to the general morphological one. Synchrotron based investigations enable very high quality three-dimensional non-destructive X-ray imaging of various fossils. These methods reveal fossil internal structures with incomparable accuracy and sensitivity. It therefore allows the study of fossils that cannot be investigated by conventional microtomography either due to a high degree of mineralization or low absorption contrast. That revolution for paleontologists was initiated at the ESRF, and is now growing in many synchrotrons all around the world. Third generation synchrotron radiation sources, and the ESRF in particular, appears as an almost ideal investigation tool for paleontologists. This talk will present different imaging aspects and the paleontological issues that can be addressed using several examples, as well as the ongoing developments of paleontology at the ESRF: the future of our past.