The School of Engineering
Portsmouth 'dragons' take to the air
Mon, Jun 21, 2010
The ‘dragons of the air’ plunge thousands of commuters, tourists and visitors to Britain’s most prestigious science festival back millions of years to when dinosaurs roamed the earth.
The exhibit includes three pterosaurs suspended in flight overhead and two standing models tall enough to look a giraffe in the eye.
The pterosaurs are the ‘wow-factor’ of the Royal Society’s prestigious ten-day summer science exhibition and were commissioned to help excite interest in science.
The team from Portsmouth behind the models are Dr David Martill, Bob Loveridge and palaeoartist Dr Mark Witton. http://www.port.ac.uk/departments/academic/sees/
Dr Witton said: “No-one has attempted to recreate pterosaurs on such a grand scale before.
“We’ve made some of the most accurate models of giant pterosaurs and, so far as I know, we are the only model makers who’ve taken all modern understandings of their anatomy and footprints into account for our work.
“Not only are we attempting to show how large these animals were, but we’re trying to show how they lived, how they reproduced, fed and fought.
“From an artistic point of view, I’ve had to twist my head around complicated aspects of restoration like wing membrane folding, foot placement and making animals that could, theoretically, switch between flying and walking postures.”
Quick view: Portsmouth ‘dragons’ take to the air
Despite Dr Martill and Mr Loveridge’s years of experience mounting large-scale exhibitions, recreating these giant beasts brought a host of scientific, technical and engineering challenges.
Working with staff from other departments including Mechanical and Design Engineering, hordes of students and leading hovercraft engineering firm Griffon Hoverwork, it took a year to build the creatures in a secret bunker under the railway arches in the city centre.
The five life-sized models are built on skeleton frames designed and built by Griffon Hoverwork using their expertise in designing and engineering craft that are able to withstand stresses and strains of extreme environments. The standing models are supported by steel frames and the flying models have aluminium frames.
Each of the flying models has a purpose-engineered frame because each model has a different flight posture.
The three life-sized flying models are built on aluminum skeleton frames designed and built by Bob and Jack Rushton using their expertise in engineering craft able to withstand stresses and strains of extreme environments. The standing models are supported by steel frames and the flying models have aluminium frames.
Each of the flying models has a purpose-engineered frame because each model has a different flight posture.
Bob Rushton said: “Most engineering has very simple geometry so it's quite easy to model but modelling a pterosaur skeleton is very different – natural shapes like legs and wings present a real and refreshing challenge and I learnt a lot in the process.
“We needed a very comprehensive computer aided design model and a new approach to the drawings to be able make the frames. My son Jack had his doubts about how this could be done but taking it one step at a time we got the first one built and when it was all assembled it is was a fantastic sight. Building the first one was hard work but we soon got the problems ironed out and the second and third were much easier.
“Working with my son to build these was an interesting experience and not without friction at times but we made a good team and we are still friends, I think. Both of us are really looking forward to seeing the finished product hanging beside the festival theatre.”
Staff and students shaped the foam body parts and helped add the surface details including fur, leg scales, crests and claws, based on current research revealing what giant pterosaurs looked like and how they lived.
About 130 different species of the flying reptile have been discovered ranging in size from the size of a thrush to a small fighter plane, but the models flying over London are of the Texan pterosaur Quetzalcoatlus, the largest animal ever to fly with a wingspan up to 30ft and a mass of nearly a quarter of a tonne.
The team based their design of the pterosaurs, which dominated the skies from the late Triassic when pterosaurs developed powered flight to the end of the Cretaceous Period – 220 to 65.5 million years ago – on fossil fragments.
Portsmouth palaeontologists have travelled the globe searching for fossil fragments and have found some traces of pterosaur soft tissue revealing details of their musculature, skin, blood vessels and even brain shape. Such finds, notably in China, Brazil and Germany, have enabled them to reassemble skeletons, examine the biomechanics of how they flew and walked, and to learn much about the way they lived.
It is this fund of information that has allowed them to recreate these models and show the world for the first time the scale and magnificence of these creatures.
Dr Martill said: “Pterosaurs are just fascinating, iconic animals. They have no living descendant so everything we know about them comes from fossil remains – it’s like solving a cryptic puzzle.
“Some were enormous creatures with wingspans three times larger than any living bird. We are advancing our knowledge about these animals all the time and we hope that by reconstructing the largest animals to use powered flight we can also learn more about the mechanics of flight.”
The richest source of pterosaur remains in Britain were found near Cambridge in deposits that were dug up and burned to make fertiliser in the 1800s.
The word pterosaurs means ‘winged lizard’. They were an enormously successful group of flying reptiles for 160 million years until they became extinct 65 million years ago. They have fascinated scientists and lay people since their discovery in 1784 and have found their way into popular culture appearing in novels, films and poems.
Dr Martill and Mr Loveridge have mounted large-scale pterosaur exhibitions before including at Buckingham Palace. Some of the team’s findings since beginning work on the models will be presented at a conference on pterosaurs this August in Beijing.
The name Quetzalcoatlus comes from an Aztec deity who can appear as a feathered serpent.
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You can find out more about the pterosaurs and the exhibition on our special website www.port.ac.uk/pterosaurs
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