AncientCode

Scientists discover feathers arose 100 million years before birds

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When we see a feather on the ground we immediately think of birds. You almost can’t think of one without the other, but a recent study of thousands of fossils in China reveals that feathers came long before birds were ever on the scene — at least 100 million years before.

 

Amazingly, these fossils show that many species of non-avian dinosaurswere feathered, Sci-News reports. Some dinosaurs even bore feather types that don’t exist in today’s birds.

An illustration of feathers on an early dinosaur
The small dinosaur Kulindadromeus zabaikalicus, by Nobu Tamura, license CC SA 4.0 via Wikimedia Commons

These discoveries stretched the discovery of feathers all the way back to at least 175 million years ago — an estimated 25 million years before Archaeopteryx, still considered by many to be the earliest bird.

But an even bigger surprise happened earlier this year when paleontologists discovered pterosaurs also had feathers — four kinds, in fact.

 

 

Feathers on a pterosaur
Illustration of a feathered pterosaur by Yuan Zhang via The Journal of Nature Ecology & Evolution

“The oldest bird is still Archaeopteryx first found in the late Jurassic of southern Germany in 1861, although some species in China are a little older,” said Mike Benton, professor of vertebrate paleontology at the University of Bristol, in a press release. “Those fossils all show a diversity of feathers — down feathers all over the body, and long, vaned feathers on the wings. But since 1994, paleontologists have been contending with the perturbing discovery, based on hundreds of amazing specimens from China, that many dinosaurs had feathers.”

Initially, the first dinosaur fossils that bore evidence of feathers were more or less the same age as those showing the earliest evidence of feathers in birds, UPI reports.

 

“This was not so hard to believe,” said paleontologist Baoyou Jiang, from the University of Nanjing. “So the origin of feathers was pushed back at least to the origin of those bird-like dinosaurs, maybe 200 million years ago.”

But then scientists found feather-like whiskers on the body of a small dinosaur that lived in Russia. They realized it was time to rewrite the story of feathers.

A small feathered dinosaur
Another representation of the small dinosaur Kulindadromeus zabaikalicus. It lived in what is now Siberia. Illustration by Andrey Atuchin via Sci-News.

“Then we had the good fortune to work on Kulindadromeus zabaikalicus, a feathered plant-eating dinosaur that lived in the lake-dotted lowlands of Jurassic Siberia between 169 to 144 million years ago,” said the study’s co-author Dr. Maria McNamara, from University College Cork. “This dinosaur showed amazingly well-preserved skin covered with scales on the legs and tail and strange, whiskery feathers all over its body.”

And this turned out to be a bit of a shock for paleontologists because Kulindadromeus wasn’t a close relative of birds.

“What surprised people was that this was a dinosaur that was as far from birds in the evolutionary tree as could be imagined,” McNamara said. “Perhaps feathers were present in the very first dinosaurs.”

Another feathered dinosaur
The early Cretaceous dinosaur Yutyrannus is the largest dinosaur currently known to have proto-feathers. Screen capture by PBS Eons via YouTube video

Chickens and other modern birds have scales on their legs or necks and in this case, evolution seems to have reversed itself somewhat. In these instances, “what had once been feathers had reversed to be scales,” said another co-author, Dr. Danielle Dhouailly, from the University of Grenoble.

 

“In fact, we have shown that the same genome regulatory network drives the development of reptile scales, bird feathers, and mammal fur,” she said. “Feathers could have evolved very early.”

But the biggest breakthrough of all came with the discovery that two new pterosaurs from China were also feathered, the University of Bristol reported in a press release.