Triassic turtles of France: the first European Rhaetian stem turtle taxon (clades Testudinata, Proterochersidae)

The earliest turtles (clade Testudinata ) are known from the Norian (middle Late Triassic) and soon after their appearance they became speciose and widespread. However, their record in the later part of the Late Triassic (Rhaetian) remains very scarce. Herein, we present the first European representatives of the clade from that age. Bartassochersis lopezi gen. et sp. nov. from the Rhaetian Formation of France is recovered here as a proterochersid and presents a number of unique, autapomorphic characters, hinting at the previously unknown morphological diversity of stem turtles in the latest Triassic. This landscape is supplemented by a find of an indeterminate, but probably remarkably small-bodied species from the ‘Grès infraliasiques’ Formation. Previously uncharted regions and latest Triassic strata of Pangaea may, therefore, still hide unknown testudinates.