Scientists and students teamed up to create the gigantic models of flying pterosaurs now terrifying commuters and tourists on London's South Bank. University of Portsmouth palaeobiologists and engineers spent nine months working with a local hovercraft firm to construct the steel and aluminium beasts. The standing and suspended models - unveiled as the centrepiece of the Royal Society's 350th anniversary exhibition - are of the Texan pterosaur Quetzalcoatlus, the largest flying animal in history. It had a wingspan of approximately 30ft and a mass of nearly a quarter of a tonne. Pterosaurs dominated the skies from the late Triassic to the end of the Cretaceous period, 220 million to 65.5 million years ago.