The clam shrimp fauna (Spinicaudata, Crustacea) of the Jurassic/Cretaceous Purbeck Limestone Formation of southern England (United Kingdom)

Abstract A Purbeck clam shrimp (Subclass Phyllopoda, Order Diplostraca) fauna is described based on a new collection, containing Liograpta subquadrata (Sowerby in Fitton, 1836) and Carapacestheria? lulworthensis sp. nov. from the Freshwater Beds, and an unidentified taxon from the Caps and Dirt Beds of the Purbeck Limestone Formation (Tithonian–Valanginian) of southwest England (UK). The scanning electron micrographs clearly show that Liograpta has puncta on growth bands near the umbo; puncta also occur between the radial lirae on the middle and ventral parts of the carapace. This newly identified type of carapace ornamentation does not occur in previously described Liograpta species from localities outside the UK, which should be moved out of Liograpta (Novozhilov, 1954). The Middle Jurassic Wolfestheria patagoniensis (Tasch in Tasch and Volkheimer, 1970) from Argentina has typical puncta and radial lirae ornamentation, and it should be assigned to Liograpta.