My major research interests are centred on the evolutionary palaeobiology of dinosaurs and other extinct amniotes. In addition, I am involved in projects to investigate macroevolutionary mechanisms, the evolution of Mesozoic terrestrial ecosystems and potential biases in the fossil record. Research is concentrated in three main areas: 1. Pattern and process in macroevolution. Controls on dinosaur diversity through time; testing of plant–dinosaur co-evolutionary scenarios; clade-clade interactions; correlated progression; influence of the rock record, collection bias and climate on fossil reptile diversity. 2. Functional morphology, palaeobiology and palaeoecology of herbivorous amniotes, principally sauropodomorph and ornithischian dinosaurs. 3. Taxonomic, systematic and faunal revisions of dinosaurs and other extinct reptiles (including lizards, plesiosaurs and ichthyosaurs).