NewNothosaurusskulls from the Lower Muschelkalk of the western Lower Saxony Basin (Winterswijk, the Netherlands) shed new light on the status ofNothosaurus winterswijkensis

Abstract

AbstractThree nothosaur skulls from the Lower Muschelkalk (Lower Anisian) locality of Winterswijk, the Netherlands, were recently acquired by museum Twentse Welle (Enschede) and have thereby become available for scientific description. Thus, these skulls had been identified asNothosaurus winterswijkensis, but upon examination these skulls challenge the status of thisNothosaurus species. All diagnostic characters are somehow discredited, but the material can also not be unequivocably be considered asNothosaurus marchicus, which is the only other obvious candidate. As these fossils originate from the same strata as the type ofNothosaurus winterswijkensisand there is no reason to assume that the animals occupied different ecological niches they are more plausibly considered one species, andNothosaurus winterswijkensistherefore becomes a junior synonym ofNothosaurus marchicus. The diagnosis ofNothosaurus marchicusis enlarged to include all finds.