Ferussina petofiana sp. n. (Gastropoda, Caenogastropoda, Cyclophoridae), the oldest representative of its subfamily from the Late Cretaceous of Romania

The terrestrial gastropod Ferussina petofiana Páll-Gergely sp. n. is described from uppermost Cretaceous (Maastrichtian) deposits from the Haţeg Basin, Romania. It represents the first properly diagnosed and described snail taxon from these deposits, despite numerous earlier reports of gastropod occurrences. This new species is characterized by a depressed, mostly smooth shell, three spiral carinae on the ventral side (inside the umbilicus), and an upward-turning aperture. The last feature characterizes two European fossil snail genera, the cyclophoroidean Ferussina, and the stylommatophoran Strophostomella. The new species is classified in the former group due to its nearly circular aperture, and the presence of conspicuous spiral carinae. In contrast, the aperture of most stylommatophoran genera (including Strophostomella) is semilunar, and if raised sculptural elements are present, they are mostly radially oriented. The identification of this new taxon in the uppermost Cretaceous of Romania represents an important range extension for the genus Ferussina, and adds it to the brief list of European clades that appear to have survived the mass extinction event at the Cretaceous-Paleogene boundary.