A new symmoriiform shark and other chondrichthyan teeth from the earliest Permian of southern Brazil

The Lontras Shale (Itararé Group, Paraná Basin) is a relevant late Paleozoic fossil stratum in western Gondwana known as a Lagerstätte, as it presents a great diversity that includes plants, invertebrates, ichnofossils and a rich ichthyofauna, mainly composed by exceptionally well-preserved actinopterygians. The chondrichthyan remains reported here are represented by three isolated teeth, collected in dark gray levels of the Lontras Shale from an outcrop known as Campaleo, located in Mafra municipality, northeastern region of the Santa Catarina State, south Brazil. One of these teeth is considered a new genus and species, which represents the first Brazilian Symmoriiformes species known so far, while the other two are attributed to undetermined Chondrichthyes. These chondrichthyans lived alongside brachiopods, poriferans, conodonts, actinopterygians, and crossopterygian fishes in cold waters of a periglacial environment during the earliest Asselian (Cisuralian, Permian) that represents the terminal stage of the Gondwanan Glaciation. Keywords: Cisuralian, Asselian, Paraná Basin, Campo Mourão Formation, Lontras Shale.