Dr Witton said: ''Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may simply launch themselves into the air from a standstill.
''Previous theories suggested that giant pterosaurs were too big and heavy to perform either of these manoeuvres and therefore they would have remained on the ground.
''But when examining pterosaurs the bird analogy can be stretched too far.
''These creatures were not birds, they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass.
''They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory.
''The anatomy of these creatures is unique.''
Their research, published today in the international Public Library of Science journal, PLoS ONE, follows claims that pterosaurs were too heavy to take off like birds.
But Drs Witton and Habib suggest that the creatures, with up to 50kg of forelimb muscle, could easily have launched themselves into the air despite their massive size and weight.
Previous theories have asserted that giant pterosaurs could have been six metres tall with a wingspan of up to 12 metres but the researchers argue that five metres high with a 10 meter wingspan would have been more realistic.
Dr Witton said: ''The size of the flight muscles in a giant pterosaur would be incredible: they alone would be up to 50kg (110lbs) and account for 20% of the animal's total mass providing tremendous power and lift.''
Q: What does a 15 foot tall flying dinosaur eat?
A: Anything it wants! Bwaha!
Here is the actual journal article, its got math in it and everything. In case any Lefties want to look, there are pictures too. ~:)
The Phantom Flying Dinosaur Hunter