Plesiochelyidae are a major component of Late Jurassic shallow marine environments throughout Europe. However, the taxonomy of the plesiochelyid turtles is rather confused. Over the years, many taxa have been synonymized with Plesiochelys etalloni , one of the first described species. However, the holotype of P. etalloni (and only specimen known from the type locality) was lost for more than 150 years. This specimen has been recently rediscovered in the collections of the Musée d'archéologie du Jura in Lons-le-Saunier, France. For the first time since its original description in 1857, the holotype of P. etalloni is redescribed and compared to relevant material. The taxonomical status of this taxon is revised accordingly. Based on the morphology of the newly rediscovered holotype, the species P. solodurensis , P. sanctaeverenae and P. langii are synonymized with P. etalloni . Known skull-shell associations for P. etalloni are re-evaluated in light of the new morphological information available since the rediscovery of this holotype specimen. Finally, we confirm that Plesiochelys is represented by a single species in Solothurn, Switzerland.