The ‘Crystal Palace Dinosaurs’ are a series of sculptures of extinct animals including dinosaurs, other extinct reptiles and mammals, which can be found in the grounds of the Crystal Palace in London. Commissioned in 1852, these are the earliest examples of dinosaur sculptures in the world. In fact, the first dinosaurs had only recently been discovered some 30 years earlier. Why were these models built? And what do they tell us about early scientific hypotheses of dinosaurs and other extinct animals? To answer these questions we talk Joe Cain, Professor of History and Philosophy of Biology at University College London.