Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous) 1Institute for Life Sciences, University of Southampton, Southampton, United Kingdom 2Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, United Kingdom 3School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, Southampton, United Kingdom DOI 10.7717/peerj.15453 Academic Editor Fabien Knoll Subject Areas...