BEIJING, March 20 (Xinhuanet) -- An ancient
treetop-living lizard that lived during the Early Cretaceous period about 150
million years ago glided through the air using a wing-like membrane stretched
across elongated ribs, a new fossil found in China reveals.
Named Xianglong zhaoi, the specimen is about 6 inches
long and its immature features suggest it died at a young age, according to
details in the March 19 issue of the journal for the Proceedings of the National
Academy of Sciences.
The fossil,described by Xing Xu of Shenyang Normal
University and his colleagues, was discovered in the Liaoning Province in
northeastern China, a site that has yielded a treasure trove of feathered
dinosaurs and early bird remains in recent years.
Xianglong's gliding membrane, called a "patagium," is
stretched across eight elongated dorsal ribs. Fully expanded, the layer of
stretchy skin would have spanned about 4.5 inches across.
Xianglong had curved claws that would have enabled it
to dwell in treetops, from whose high perch it could launch into the air. Once
airborne, the little lizard could probably glide farther than modern flying
lizards, perhaps as far as half a football field at a time, Xu said.
The lizard's "wings" share several similarities with
the wings of modern fast-flying birds, suggesting it might have been more nimble
in the air than other gliding lizards.
Most gliding animals, such as "flying" frogs and
squirrels, use a membrane spread between their toes or between their body and
legs to stay airborne. A gliding membrane spread between elongated ribs is only
known to occur in an ancient lizard-like animal that lived during the Late
Triassic era and certain living dragon lizards in Southeast Asia.
"It is really amazing to see evolution making nearly
identical structures in animals of different origins spanning such a long
history," Xu told LiveScience.
(Agencies)