A partial rostrum of the Porbeagle shark <i>Lamna nasus</i> (Lamniformes, Lamnidae) from the Miocene of the North Sea basin and the taxonomic importance of rostral morphology in extinct sharks
A fragmentary rostrum of a lamnid shark is recorded from the upper Miocene Breda Formation at Liessel (Noord-Brabant, The Netherlands); it constitutes the first elasmobranch rostral process to be described from Neogene strata in the North Sea Basin. Based on key features of extant lamniform rostra and CT scans of chondrocrania of modern Lamnidae, the Liessel specimen is assigned to the porbeagle shark, Lamna nasus (Bonnaterre, 1788). In addition, the taxonomic significance of rostral morphology in extinct sharks is discussed and a preliminary list of elasmobranch taxa from Liessel is presented
