Morphology, histology and identification of the ‘granicones’ from the Purbeck Limestone Formation (Lower Cretaceous: Berriasian) of Dorset, southern England

摘要: Abstract The identification of the ‘granicones’, small, conical and shield-like phosphatic structures with a pustulate surface ornamentation, from Purbeck Limestone Formation Dorset, has been problematic for over 130 years. They have interpreted as osteoderms theropod or ornithischian dinosaurs, lizards crocodiles, though only circumstantial evidence was presented in support these hypotheses. Here, we provide anatomical, histological geological that demonstrates true affinities granicones: they are limb turtles may be referable to either Helochelydra (= Tretosternon ) anglica ‘ ’ bakewelli .