fossils

Jianianhualong, the dinosaur with feathers made for flying

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Franz
Anthony

Editor and Artist
One fossil dinosaur from China shows that modern asymmetrical feathers, normally associated with flight, also evolved in grounded dinosaur groups.

Roughly 125 million years ago back in the Cretaceous, the province of Liaoning was full of lakes and forests, with a diverse fauna of dinosaurs and pterosaurs. Today it is famous for its exquisite preservation of its past inhabitants including feathered dinosaurs. One of them was Jianianhualong, a fluffy two-legged dinosaur, which was roughly the size of today’s turkeys.


While the discovery of feathered dinosaur fossils is no longer a big surprise, it is the type of Jianianhualong’s feather that makes it special.


Dinosaurs started sporting feathers long before they developed the ability to fly. Early feathers, however, were more of a fuzz than the quill-shaped vanes we are familiar with today. The capability of flight is said to arise when wing and tail feathers started to develop asymmetry, a feature seen in today’s birds. Such a feather is recognizable by its shape – it is wider on one side than the other.


This is the kind of feather that makes Jianianhualong special. Jianianhualong belongs to a group of dinosaurs called troodontids that likely weren’t able to fly. Therefore, this transitional feature shows that asymmetrical feathers appeared much earlier in the dinosaurs’ evolutionary tree. The authors of the study suggested that this feature is commonly shared by the member of the group Paraves, which includes troodontids, modern birds, and dromaeosaurs, also known as raptors.


Right now, only the tail of Jianianhualong is confirmed to have these feathers. But its likely that the feathers on its wings and legs are also asymmetrical.


It is not yet known why dinosaurs evolved asymmetrical feathers in the first place. As they keep their shape in the wind, the researchers suggest this would have helped dinosaurs to perform longer jumps and slower descents. It’s also possible that the feathers helped the dinosaurs to attract their mates. As we discover more feathered dinosaurs all over the world, we may soon learn more about their origins.


Read the original research in Nature.

Image Credit: Fabrizio De Rossi

8e6ac47821297aeee8c843e680637dca

Franz
Anthony

Editor and Artist


http://sulc.us/qr9lh
http://www.eartharchives.org/articles/jianianhualong-the-dinosaur-with-feathers-made-for-flying/