And judging by the long horny sheaths covering its claws, "we think this pterosaur lived at least part of its life in the trees."
The 12-inch-long (30-centimeter-long) pterosaur had a 35-inch (90-centimeter) wingspan—roughly the same as a mallard duck's—with remarkably well-preserved membranes.
"It must have been rapidly buried after it died, perhaps by a river or maybe inside a lake," Kellner said. "Otherwise its soft tissue would have rotted away quickly and not been preserved."
Previous studies of pterosaur wings had shown that each membrane contains a single layer of closely packed structural fibers unique to pterosaurs called actinofibrils. These fibers are thought to have helped reinforce the wing.
When Kellner and colleagues shone ultraviolet light on J. ninchengensis's wings, the team found that the membranes had at least three layers of actinofibrils running in a crisscross pattern.
"This is the first time a wing membrane like this has been reported before," said paleozoologist Eberhard Frey at the State Natural History Museum in Karlsruhe, Germany, who did not participate in this study.
Both Frey and Kellner note that researchers are still trying to find out what pterosaur actinofibrils were made of, which would offer insight into the fibers' exact purpose.
"Were they muscle? Collagen? Keratin? Stiff? Elastic?" Kellner asked.
In general, he said, the new find shows that pterosaur wings are "much more complex than we thought."
Findings will appear in the August 5 issue of the Proceedings of the Royal Society B.
SOURCES AND RELATED WEB SITES