A pelomedusoid (Testudines, Pleurodira) plastron from the Lower Cretaceous of Alagoas, Brazil

The oldest records of crown-Pleurodira turtles were from the Aptian (Lower Cretaceous) of northeastern Brazil and northern Africa. Recently, a new side-necked turtle was reported from the Morro do Chaves Formation, Sergipe-Alagoas Basin, Brazil, extending the First Occurrence Datum of that crown-clade to the Barremian. Here, we report a partial panpelomedusoid plastron from the shales of that same stratigraphic unit, which may represent a previously undescribed taxon. Its small size, loose sutures, and the strong constriction in the xiphiplastra, suggest that it corresponds to a juvenile individual.