Palaeontologists have unveiled an extraordinary prehistoric 'flying' reptile which lived 235 million years ago.
The kuehneosaurs glided through the subtropical forests of Europe using scaly 'wings' that could carry it distances of more than 30ft.
Experts say the lizard-like reptile, which grew up to 2ft long, used extensions of their ribs to form large gliding surfaces on the sides of their body.
The scientific community is united in the belief that birds descended from reptiles 50 million years later making the kuehneosaurs the world's first 'bird'.
The kuehneosaurs glided through forests 385million years ago
The long-extinct species was first unearthed in the Britain by Archaeologists in the 1950s, but until now their aerodynamic capability had not been studied.
Their rudimentary 'wings' were always assumed to be some form of flying adaption, but scientists at the time lacked the necessary technology to test the theory.
But earlier this year, experts from Bristol University investigated both types of kuehneosaurs found in the UK - kuehneosuchus and kuehneosaurus - for the first time.
The team built lifesize models of the creatures and used techniques usually employed to test prototype aircraft - including a wind tunnel - to discover their amazing flying ability.
Their pioneering findings, published this week by the Paleontological Association, have turned the history of winged flight on its head.
Today German palaeobiologist Koen Stein, who led the study, said: '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 University.
'Surprisingly, we found that kuehneosuchus was aerodynamically very stable. Jumping from a tree, it could easily have crossed 9m (29ft) before landing on the ground.'
The species, which inhabited the warm late Triassic period from 235 to 200 million years ago, was first discovered in the UK inside an ancient cave system near Bristol.
Both types of kuehneosaurs lived 80 million years before the largest dinosaurs of the Jurassic period, and 50 million years before the earliest known bird, archaeopteryx, which lived in what is now southern Germany.
Mr Stein and his colleagues used a number of different materials to reconstruct the creatures' scaly wings, which they then tested using specialist aerodynamic equipment.
Aerospace engineers suspended the models in a wind tunnel and passed a jet of hot air over the models' bodies.
This gave experts a detailed idea about the air flow over their wings, and the distance they would have glided from tree-top to tree-top in search of food and to escape larger predators. But Mr Stein admitted the task wasn't always straightforward.
He added: 'We 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 they probably did not have such features.'
Mr Stein, who now works at the prestigious Institute of Palaeontology at Bonn in Germany, carried out the research with Colin Palmer, Pamela Gill and Michael Benton from Bristol University's Department of Earth Sciences.
Department head Professor Michael Benton said: '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.'