How ancient reptiles flew before birds
Tuesday, 15 Jul 2008 00:01
How Kuehneosaurus may have looked gliding through the air
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Prehistoric reptiles used their rib cages to fly some 50 million years before the world's oldest birds, scientists have discovered.
Researchers at the University of Bristol found that extinct reptiles called kuehneosaurs used extensions of their ribs to form large gliding surfaces on the side of the body.
The reptiles were up to two feet long and were first found in the 1950s in an ancient cave system near Bristol.
Researchers studied two of the wings of the kuehneosaurs by modelling different skin flaps over the wing area.
They also built webbed hands and feet and had an extra skin membrane between the legs on the models, but these made the flight of the animals unstable, suggesting that they probably did not have such features.
Writing in the journal Palaeontology, the researchers argue that Kuehneosuchus was a glider (it has elongated 'wings'), while Kuehneosaurus, with much shorter 'wings', was a parachutist.
As the two forms are so alike in other respects, it is possible that they are males and females of the same animal.
"We didn't think kuehneosaurs would have been very efficient in the air, but all the work up to now had been speculation, so we decided to build models and test them in the wind tunnel in the department of aerospace engineering at Bristol," commented lead researcher Koen Stein.
"Surprisingly, we found that Kuehneosuchus was aerodynamically very stable. Jumping from a five-metre tree, it could easily have crossed nine metres distance before landing on the ground. The other form, Kuehneosaurus, was more of a parachutist than a glider."
Professor Michael Benton, a member of the research team and head of department in Bristol, added: "Palaeontologists are keen to understand how all the amazing animals of the past operated and by collaborating with aerospace engineers we can be sure that model-making and calculations are more realistic."
