BEIJING: Fossil findings of an ancient arboreal lizard in northeastern China's Liaoning province indicate that the reptile could glide through air using a membrane it could stretch across its elongated ribs.
The lizard, named Xianglong zhaoi, was alive in the early Cretaceous period, which is about 150 million years ago. The fossil that was found is about six inches long and scientists believe the specimen to be immature, meaning it would have died at a young age.
The details of the finding are reported in the latest issue of the journal for the Proceedings of the National Academy of Sciences.
Xing Xu of Shenyang Normal University in China, and his colleagues, who conducted studies on the specimen, said the fossil was discovered in a region, known to have yielded several other species, including feathered dinosaurs and early bird remains.
The scientists found that reptile's gliding membrane, which is called “patagium,” is stretched across eight elongated dorsal ribs. When it is fully expanded, it would have spanned about 4.5 inches. The reptile had curved claws helping it to stay on treetops and then launch itself into the air. The scientists believe it could probably glide a longer distance than the modern-day flying lizards.
Many of the gliding animals that exist today like the flying frogs and squirrels make use of a membrane found between their toes or between their body and legs to glide. Scientists say a membrane spread between ribs is only known to occur in an ancient lizardlike animal that lived during the Late Triassic era and certain living dragon lizards in Southeast Asia.
Xu suggests that such a membrane got evolved by convergent evolution, the process by which different species came into existence with the same solution to the same problem.
