This is a video about Coelurosauravus.
From New Scientist:
Ancient lizard extended its rib bones to glide
* 21:00 19 March 2007
* NewScientist.com news service
* Roxanne Khamsi
Ancient lizards used their ribs to help them glide through the air, a new fossil find has revealed.
It shows a wing-like membrane spread over elongated ribs.
Xing Xu, at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, and colleagues discovered the specimen, of the species Xianglong zhaoi, in the Liaoning Province of the country.
The fossil is 125 million years old and measures 15.5 centimetres long, including a slender 9.5-centimetre tail.
The animal has eight elongated ribs on each side that support a superbly preserved wing-like membrane.
They note the membrane is in a half-open position, which probably reflects folding of the wing after the lizard’s death.
The structure probably helped the lizards glide through the air to catch insect prey, the researchers speculate.
Previous excavations revealed that the Coelurosaurovus [sic; Coelurosauravus], Icarosaurus and Kuehneosaurus reptiles found in Germany, North America and UK, respectively, all had similar rib-supported wings.
But Sankar Chatterjee, a palaeontologist at Texas Tech University in Lubbock, US, explains that the new discovery is special because, “unlike other Permian and Triassic gliding forms, the Chinese genus Xianglong is a true lizard”.
He adds: “This is also the first fossil evidence that unequivocally demonstrates an impression of the skin around the edge of the ribcage.”
The modern-day Draco lizards in Southeast Asia have wings supported by ribs that help them glide.
But Robert Carroll, a vertebrate palaeontologist at McGill University in Montreal, Canada, says it is “improbable” that Draco lizards descended from the Xianglong zhaoi lizard: “There are more gaps than there are links” between the ancient and modern lizards, he notes.
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0609552104)
See also here.
Powered flight evolved three times in vertebrates, all converting their forelimbs into wings. The body plan modifications among gliders however are far more diverse, including a new Triassic reptile with long legs bearing a wing membrane: here.