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.”
Dr Habib added: ”Scientists have struggled for decades to figure out how giant pterosaurs could become airborne and some recent proposals have simply assumed it must have been impossible.
”But they may have approached the problem from the wrong end, instead of taking off with their legs alone, like birds, pterosaurs probably took off using all four of their limbs.
”By using their arms as the main engines for launching instead of their legs, they use the flight muscles, the strongest in their bodies, to take off and that gives them potential to launch much greater weight into the air.
”This may explain how pterosaurs became so much larger than any other flying animals known.”