Latest Oligocene amphibians from Coderet (France)

The French locality of Coderet (latest Oligocene, MP30) yielded an astonishing number of amphibian fossil remains. The studied amphibian assemblage from Coderet consists of 8,639 skeletal remains referred to 10 taxa, making it a hot spot for diversity during the Palaeogene. Urodeles are the dominant group, almost 99% of the fossils, represented by the family Salamandridae, including both subfamilies Salamandrinae and Pleurodelinae. Amongst them, Lissotriton sp. is by far the most abundant taxon (7,139 remains). Other well-represented salamanders include Chelotriton sp. (669 remains), Salamandra sansaniensis (394 remains) and Chioglossa meini (140). Although limb bones and girdle elements in salamanders are generally considered not to be highly diagnostic and rarely allow identification at family or subfamily level, this study shows that they may still display apomorphic features with potential taxonomic value through osteological comparisons of extant, dry disarticulated skeletons. Anurans are less abundant, with only 116 bones, but referred to an astonishing diversity of four families for six taxa: Bufonidae, Discoglossidae ( Latonia ragei and Latonia sp.), Pelobatidae and Ranidae ( Pelophylax sp. and Rana sp.). The biostratigraphy of the amphibians from Coderet is characteristic of the Oligocene and Miocene faunas, confirming a few changes being generally observed between Palaeogene and Neogene European faunas. Nevertheless, this very rich fauna helps to fill temporal gaps in the history of several taxa.