Cave deposits across South Wales and southwest England have yielded Late Triassic to Early Jurassic tetrapod faunas – the authors present a hitherto little studied fissure at Ruthin Quarry in South Wales. 11 taxa were identified including new genus and species named here Smilodonterpeton ruthinensis. Most of the taxa appear to be ‘primitive’, and their body sizes are small, so this could be the oldest record of insular dwarfism. Interested to read more?