Pucapristis is a prehistoric genus of saw fish whose fossils first appear in the fossil record in rocks dating from the Maastrichtian stage. Fossils of Pucapristis have not been found in any subsequent strata. Incidentally, the Maastrichtian is the final portion of the Cretaceous Period and its endpoint marks the advent of the Cretaceous–Paleogene extinction event. This major geological transition is famous for being the mass extinction that wiped out the dinosaurs.