A reassessment of the Early Cretaceous reptile ‘Patricosaurus merocratus’ Seeley from the Cambridge Greensand, Cambridgeshire, UK

The Cambridge Greensand has yielded a diverse fauna of terrestrial and marine vertebrates, including various fish, birds, dinosaurs and marine reptiles. However, this important late Early Cretaceous biome has been severely neglected and the taxonomy and systematics of most of these animals are in need of urgent revision. The small reptile ‘Patricosaurus merocratus’ was named on the basis of a partial femur and sacral vertebra and referred to the Squamata. Re-examination of the type material indicates that ‘Patricosaurus’ represents a chimera composed of indeterminate lepidosaurian and archosaurian elements and that it should be regarded as a nomen dubium. Nevertheless, the syntype femur represents the only material of a terrestrial lepidosaur to be recovered from the Cambridge Greensand. Moreover, this element is currently the largest known terrestrial lepidosaur, living or extinct, to have been recovered from the British Isles.