Why extant, why not extinct? A new extinct <i>Latonia</i> species (Anura: Discoglossidae) from the Early Pleistocene of the Apennine Peninsula provides clues on the survival of the genus in Eurasia

Pietrafitta is one of the richest Early Pleistocene localities in the Italian Peninsula and it hosts one of the latest occurrences of the discoglossid frog <i>Latonia</i> in Europe. This occurrence is here described as a new species of <i>Latonia</i>, a large-bodied frog, potentially feeding on hard invertebrates in the Pietrafitta palaeoswamp. Our first attempt at the phylogenetic reconstruction of <i>Latonia</i>, based on a matrix consisting of 20 taxa and 39 characters, placed the new Italian species within a poorly understood clade that also includes <i>Latonia caucasica</i> from the Late Miocene of northern Caucasus. Almost all other extinct <i>Latonia</i> species make up a second clade, represented in the fossil record from the Oligocene and including the youngest occurrence of the genus in Europe, from the Middle Pleistocene of Hungary. The only extant species, <i>Latonia nigriventer</i>, was the earliest branching taxon in our topology, which could be due to its unique unsculptured morphology, a trait that may represent a secondary loss during the Quaternary. The exostosis on cranial bones, which is considered a diagnostic feature of the genus, might have developed in the earliest <i>Latonia</i> in response to pronounced warming and drought. Later, starting after the Middle Miocene, this exostosis underwent a reduction process, possibly triggered by cooling, that led to Plio–Pleistocene forms sharing a narrower frontoparietal with a less pustular sculpturing. <i>Latonia dimenticata</i> is a clear example of this frontoparietal morphology. <i>Latonia nigriventer</i> may have further evolved a completely unsculptured morphology to face rapid environmental changes in the last Quaternary glacial phases and ultimately facilitating its survival into the present day. https://zoobank.org/urn:lsid:zoobank.org:pub:E0502A26-F909-4240-97CC-1C98E606322B