Washington, May 28 : A new study has found that many flying dinosaurs like Pterosaurs, preferred to walk, as they were strongly adapted for life on the ground.
The study, done by researchers at the University of Portsmouth, focuses on one particular type of pterosaur, the azhdarchids, claiming that they were more likely to stalk animals on foot than to fly.
Until now, virtually all pterosaurs have been imagined by palaeontologists to have lived like modern seabirds: as gull- or pelican-like predators that flew over lakes and oceans, grabbing fish from the water.
But a study of azhdarchid anatomy, footprints and the distribution of their fossils by Mark Witton and Dr Darren Naish shows that this stereotype does not apply to all flying reptiles and some were strongly adapted for terrestrial life.
Azhdarchids, named after the Uzbek word for 'dragon', were gigantic toothless pterosaurs. They include the largest of all pterosaurs, with some having wingspans exceeding 10 metres, and the biggest ones being as tall as a giraffe.
"Azhdarchids first became reasonably well known in the 1970s, but how they lived has been the subject of much debate. Originally described as vulture-like scavengers, they were later suggested to be mud-probers, and later still suggested to make a living by flying over the water's surface, grabbing fish," said Dr Naish.
Now, the new study has determined that Azhdarchids were probably better than any other ptersosaurs at walking because they had long limbs and skulls well suited for picking up small animals and other food from the ground.
After carefully examining the available evidence, Dr Naish and Witton concluded that azhdarchids were specialised terrestrial stalkers.
The researchers studied fossils in London, Portsmouth and Germany and compared the anatomy of azhdarchid with those of modern animals. This showed that azhdarchids were strikingly different from mud-probers and animals that grab prey from the water's surface while in flight.
Some aspects of azhdarchid anatomy, such as their relatively small padded feet and long but weak jaws often pose problems in other proposed lifestyles, but fit perfectly with the terrestrial stalker hypothesis.
According to Witton, "The small feet of azhdarchids were no good for wading around lake margins or swimming should they land on water, but are excellent for strutting around on land."
"All the details of their anatomy, and the environment their fossils are found in, show that they made their living by walking around, reaching down to grab and pick up animals and other prey," said Naish.