Popular images of the prehistoric world are filled with spiny stegosauri, placid brachiosaurs, and rampaging tyrannosaurus rex. But one image we may need to revise is that of pterodactyls flying overhead. New research suggests the winged lizards were far too massive to stay aloft, although some paleobiologists are inclined to disagree.Professor Katsufumi Sato of the University of Tokyo studied five species of soaring birds, measuring the thrust the birds require to stay aloft. He concluded that no animal that weighs more than 40kg (88lbs) could soar. The wandering albatross, which has the largest wingspan of any living bird, weighs only 22kg. Heavier birds can achieve enough thrust to take off, but cannot flap their wings quickly enough to keep their mass in the air. Pterodactyls had as much as a 15 meter wingspan, but were four times heavier than the albatross. So were pterodactyls the turkeys of the Cretaceous Period? Not according Mike Habib, a biomechanics researcher at the Johns Hopkins School of Medicine:
One possible theory is they would rely on thermals to stay aloft having dropped off the edge of a cliff. However, evidence that they could walked for considerable distances has also been discovered. Another theory is that their wings were so large that, relatively speaking, wing load was low. If a pterosaur spread its wings, staying on the ground would have been more of a problem than taking off.
So, until paleocloning resolves the question, we can hold onto our vision of pterodactyls in the skies. Pterodactyls were too heavy to fly, scientist claims [Telegraph]