Iguanodon lived from the Late Jurassic to the Late Cretaceous in Asia, Europe and North America. Iguanodon was a large herbivore whose most distinctive features were its large thumb spikes, which were used for defence against predators.

This dinosaur bone shows interesting features, such as the cavities through which blood once flowed into the bone. These 'canals' have been used as evidence that dinosaurs were warm-blooded.

If dinosaurs were warm-blooded, it may explain why they became extinct during the Cretaceous-Tertiary Mass Extinction while their cold-blooded relatives the crocodiles survived.