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Bizarre bat-winged dinosaur once soared over China

Airborne dino A dinosaur with bat-like wings once soared through the skies of what is now China.

The Jurassic dinosaur, named Yi qi, has the shortest name ever given to a dinosaur. Yi qi, pronounced "ee chee," means "strange wing."

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

"This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career," says palaeontologist Xu Xing of the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) in Beijing.

"I know the complexity of the dino-bird transition, but this new find still shocks me," adds Xu, who is the lead author of the study, published in the journal Nature.

"It demonstrates how extreme the experimentation for dinosaurs to get in air is."

He and his colleagues unearthed the remains for Yi qi at Hebei Province in China.

At first, the scientists puzzled over rod-like bones that extended from each wrist of the tiny dinosaur that weighed about the same as a modern pigeon. Colleagues joked that the dino used the bones as ski poles or giant chopsticks.

Co-author Corwin Sullivan, a Canadian palaeontologist now based at the IVPP, determined their real purpose after he pored over scientific literature on flying and gliding animals for a different project.

"I came across a paragraph in a textbook that said flying squirrels have a strut of cartilage attached to either the wrist or elbow to help support the flight membrane. I immediately thought, wait a minute, that sounds familiar!" says Sullivan.

Further investigation of Yi qi's remains uncovered patches of membranous tissue that covered its wings.

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 says.

Given the dinosaur's bat-like wings, "Yi qi was mainly gliding, perhaps in combination with a bit of awkward flapping," he adds.

The researchers believe Yi qi was a scansoriopterygid - a group of dinosaurs only known from China that were closely related to primitive birds, such as the Archaeopteryx.

Although the dinosaur shared traits with bats, it wasn't related to them, since bats are mammals. It therefore represents a striking example of convergent evolution.

Other unusual characteristics

Yi qi had other noteworthy characteristics, aside from its unusual wings.

Sullivan says that its arms were proportionally very long, with each arm ending in a hand that had three clawed fingers. One of the fingers was very elongated, with it and the other fingers helping to support the flight membrane.

Its head was small, but equipped with tiny peg-like teeth, which it probably used to eat prey such as insects, small mammals and lizards.

As for what might have eaten Yi qi, Xu said, "I would not be surprised to see some primitive tyrannosaurs around."

While some studies theorise that scansoriopterygids evolved to become birds, Xu and his team think otherwise. They instead place dromaeosaurids and troodontids closer to birds.

"Yi qi seems to have been part of a Jurassic radiation of small dinosaurs that were experimenting with different ways of becoming airborne," Sullivan says.

"All these dinosaurs were closely related to birds and, in fact, it's best to think of birds as just one group that emerged during that evolutionary radiation - a group that happened to be extremely long-lived and successful."

This story was originally published on Discovery News