Claudiosaurus and the Permian puzzle: uncovering the roots of Modern Reptiles

The origin of modern reptiles is one of the most nebulous and debated questions in vertebrate paleontology. This is due to the very sparse fossil record of non-saurian neodiapsids (the forerunners of saurians) and the preservation state of the rare specimens we have access to – small bones encased in a dense nodular matrix – that hampers detailed observations, as well as traditional μCT examinations. This is a great obstacle to our understanding of their anatomy, phylogenetic relationships, and paleobiology. Our study focuses on Claudiosaurus, a semi-aquatic neodiapsid from the Malagasy Permian. We aim to scan the few specimens preserving cranial structures, a rare source of new anatomical information. These specimens have proven inaccessible to standard μCT, and require synchrotron imaging to obtain results suitable for precise segmentation and histological study. This will enable a detailed description, assessment of ontogeny, and a better understanding of the origins of reptiles.