This 'bizarre-looking, buck-toothed' dinosaur that could fit in your palm flew around the Jurassic skies like a bat

• Scientists have discovered fossils from a 163-million-year old flying dinosaur in China.
• In a new study, paleontologists say the creature had leathery wings like a bat, rather than feathery wings like a bird. It flew in a similar way to modern-day flying squirrels.
• This new fossil, in combination with previous discoveries of similar dinosaurs, shows that flying dinos existed hundreds of millions of years ago.
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More than 160 million years ago, the Jurassic skies were replete with winged creatures.

Some of these fliers may have sported feathers (as did some of their compatriots on the ground, like baby T. rexes). But a new discovery suggests that at least one flying dinosaur boasted leather over feather, swooping through the air over modern-day China with wings akin to a bat's.

In a recent study published in the journal Nature, scientists describe the discovery of a 163-million-year-old flying dinosaur that was about the size of an urban pigeon.

"This fossil seals the deal - there really were bat-winged dinosaurs," Stephen Brusatte, a paleontologist at the University of Edinburgh who was not involved with the study, told Science magazine.

Jingmai O'Connor, a co-author of the new study, told the New York Times that the creature probably glided through the air in a manner "halfway between a flying squirrel and a bat."

Flaps of skins stretched between bones helped this dinosaur fly

The study authors named the new fossil Ambopteryx longibrachium; the first word means "both-wing," while the second means "long arm."

"You could have fit it in your hand," O'Connor told Science. "It would have been this tiny, bizarre-looking, buck-toothed thing like nothing alive today."

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O'Connor added that she and her colleagues think Ambopetryx males might have had long, ornamental tail feathers to attract females. The dinosaur probably also had a downy coat of peach fuzz, but those feathers would have been too tiny to be used in flight.

The bat-like wings were the dinosaur's most startling feature, though.

Typically, birds generate the lift they need to take off and stay in flight by flapping feathered wings. The layered feathers form a curved surface called an airfoil that the moving air pushes upward, helping the bird to fly.

On the other hand, the airfoils on bats are formed from flaps of skin that stretch between the animals' arm bones. Air flow under and around these membranous flaps of skin generates the lift. A similar structure has been found on wings of extinct pterosaurs (flying reptiles that were dinosaur cousins).

Fossil evidence shows that the newly discovered flying dinosaur had similarly elongated forearms, with flaps of skin spanning the gaps between the bones. The skin was held in place by a rod of cartilage on the animal's wrist called a styliform.

It's a bird... It's a bat... It's a flying dinosaur

Birds and bats each evolved winged flight separately, and each group of animals used a different type of wing to get airborne.

Paleontologists were confident that some dinosaurs could fly, too - some dinosaur groups eventually evolved into the ancestors of modern-day birds - but they weren't sure how the prehistoric creatures gained the ability.

Then in 2015, scientists unearthed a dinosaur named Yi qi (meaning "strange wing" in Mandarin) in northwestern China. It was almost as small as the newly discovered Ambopteryx, and it sported similar flaps of skin stretched between its forearms and torso. But the fossil was too poorly preserved for paleontologists to determine whether Yi qi could fly like a bat. The researchers classified it as a type of tiny Therapod dinosaur (the same family the T. rex belonged to) that spent most of its time climbing and gliding between trees.

Now, Ambopteryx provides evidence that these Jurassic dinos' bat-like wings did enable them to fly, at least partially.

However, no dinosaurs of this type lived past the end of the Jurassic period 145 million years ago. To O'Connor, that indicates that Ambopteryx's evolutionary strategy for flight was not as successful as bird ancestors' feathers. For that reason, the study authors concluded that these bat-like wings "probably represent a short-lived experimentation" with flying behavior among dinosaurs.