Article: The trilobite genus Phillipsinella from the Ordovician of Scandinavia and Great Britain
David L. Bruton
Phillipsinella fornebuensis sp. nov. and P. preclara sp. nov. are described from the Caradoc Lower Chas-mops Shale (4ba) and the Upper Chasmops Limestone (4bS1-2) respectively of the Oslo Region, Norway, together with figured but unnamed specimens from equivalent horizons and older in Sweden. Material of P. preclara sp. nov. is also figured from the highest Pusgillian of northern England. The Norwegian material provides new information on muscle-scar patterns and exoskeletal surface sculpture. Well-defined glabellar lobes and furrows are described for the first time, there being three lobes in P. preclara, one lobe in P. fornebuensis. A new diagnosis is given for the genus which is retained in a separate family on account of the distinctive hypostoma. Relationship to the early scutelluids, especially Raymondaspis and Stygina, is considered likely. A classification based on the morphology of various known cranidia allows the recognition of two species groups, an Arenig-Ashgill group embracing forms from Balto-Scandinavia, eastern Ireland, Turkey, Kazakhstan, and Uzbekistan, and an Ashgill species group centred around P. parabola sensu lato known from Britain, Bohemia, Poland, and southern Sweden.