Article: Maastrichtian squaloid sharks from southern Sweden
The Maastrichtian of southern Sweden has yielded more than 2000 teeth of squaloid sharks. Seven species have been identified: Microetmopterus wardi gen. et sp. nov., Proetmopterus hemmooriensis gen. nov., Eoetmopteris cf. E. supracretaceous, Centroscymnus schmidi, Squalus ballingsloevensis sp. nov., S. balsvikensis sp. nov. and S. gabrielsoni sp. nov, Etmopterine sharks, now restricted to the cold bottom-waters of the outer continental and insular shelves and slopes, apparently thrived in the shallow coastal waters of the Kristianstad Basin during the earliest Maastrichtian. As indicated by its extremely small teeth. Microetmopterus wardi may have been the smallest known neoselachian. The Recent Centroscyllium could be an example of a restricted form of 'hopeful monster', by instantaneously having acquired a monognathic heterodonty in a single ancestral individual or litter. The type series of Eoetmopterus supracretaceous is a heterogeneous mix of Eoetmopterus and Proetmopterus. Similarly, the type series of Centroscymnus schmidi also includes Proetmopterus hemmooriensis.