At 160-mn-years old, it is older than the first known birds, such as Archaeopteryx. It also appears to be the earliest known flying non-avian dinosaur.

The fossil of a bizarre pigeon-sized dinosaur that had bat-like wings made of skin rather than feathers has been identified in China, shedding new light on the evolution of flight.
The dinosaur — named Yi qi — the shortest name ever given to a dino, which means “strange wing.”
At 160-million-years old, the dinosaur is older than the first known birds, such as Archaeopteryx. It also appears to be the earliest known flying non-avian dinosaur.
Unexpected discovery

“This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career,” paleontologist Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing said.
“It demonstrates how extreme the experimentation for dinosaurs to get in air is,” said Xu, the lead author of the study.
Researchers unearthed the remains for Yi qi at Hebei Province in China,Discovery News reported.
The rod-like bones that extended from each wrist of the tiny dinosaur and weighed about the same as a modern pigeon puzzled the scientists.
Their real purpose was determined by co-author Corwin Sullivan, a Canadian paleontologist now based at the IVPP, after he pored over scientific literature on flying and gliding animals.
Further investigation of Yi qi’s remains uncovered. While the dinosaur did have feathers, they were more like hairs, bristles or streamers, and would not have been capable of forming good aerodynamic surfaces, Sullivan said.
“Yi qi was mainly gliding, perhaps in combination with a bit of awkward flapping,” he added.
Researchers believe Yi qi was a scansoriopterygid, referring to a group of dinosaurs only known from China that were closely related to primitive birds.
The finding was published in the journal Nature.