The description and phenetic relationships of a new Ichthyosaur genus from the Upper Jurassic of England

摘要: A large and previously unknown ichthyosaur is reported from the Kimmeridge Clay (Upper Jurassic) of Stowbridge, Norfolk, England. The only valid genera described Upper Middle Jurassic are considered to be Ophthalmosaurus Seeley Nannopterygius von Huene, since Stowbridge specimen distinct these, a new genus species, Grendelius mordax gen. et sp. nov., erected. Using cluster principal coordinates analyses, G. was found have closest phenetic affinities with Platypterygius americanus (Nace) North American Cretaceous, an undescribed Triassic Switzerland, least affinity discus (Marsh).The analysis also revealed that division Ichthyosauria into latipinnates longipinnates questionable. Stenopterygius quadriscissus (Quenstedt), long longipinnate, herein shown closer latipinnate ichthyosaurs. close phenet...