Article: A new rhynchocephalian from the British Upper Trias

The skull of a new fossil reptile, Planocephalosaurus robinsonae gen. et sp. nov., is described and its affinities discussed. The description is based on approximately 750 isolated skull bones recovered from Triassic fissure infills in Carboniferous Limestone in the Bristol Channel area. The skull is diapsid, although there is usually a small gap present in the lower temporal bar. Further evidence that an incomplete lower temporal bar is not a uniquely squamate character is provided. The new reptile is compared with the eosuchians and the taxonomic position of the family Sphenodontidae is reviewed.