The sands of Ouedhref in southern Tunisia represent a geological site that is very rich in fossils. Despite this richness, these sands unfortunately remain poorly dated. My thesis aims to study this formation in its geodynamic and paleontological framework: a geodynamic study of the zone will allow for an understanding of the establishment of these sands in the context of the general progradation of continental deposits in Tunisia. A paleontological study of the fossil vertebrates will enable correct dating and repositioning of this formation among the mid-Miocene continental formations of Tunisia. Thus, understanding the history of deposits from the end of the middle Miocene to the Messinian crisis episode and discussing the importance of Tunisia in the history of the distribution of vertebrates in North and East Africa and possible migration routes to Europe.