Pictures: Dinosaur's Flashy Feathers Revealed

Tail Streamers

Illustration courtesy Mick Ellison, Science/AAAS

Limbs spread, a Microraptor shows off its iridescent plumage and two tail feathers, called streamers, in an illustration.

Hints of streamer feathers were visible in earlier Microraptor fossils, but the streamers were incomplete, explained study co-author Clarke.

"You can actually make them out, but they're broken, so you can't see the ends of them," she said.

Not until the discovery of a new Microraptor fossil in northeastern China in 2010 did scientists get their first clear picture of what the dinosaur's tail looked like.

Once thought to be a broad, teardrop-shaped surface, the tail was actually much narrower and tipped by two long feathers, the new fossils suggest.

The new findings also support a theory first proposed by Clarke in 2006 that the evolution of tail feathers in early birds was driven primarily by sexual selection rather than aerodynamics.

According to this idea, tail feathers were a costly structure that only much later became important for flight, Clarke said.

(Related picture: "Dinosaur Species Flew Like a Biplane.")

Published March 9, 2012

Microraptor Frozen in Time

Photograph courtesy Mick Ellison

A Microraptor fossil discovered in 2010 (pictured), allowed scientists to determine that the dinosaur had iridescent feathers.

"Just a few years ago, it would have been inconceivable for us to have imagined doing a study like this," study team member Ke-Qin Gao of Peking University in Beijing said in a statement.

Although its anatomy is very similar to bird anatomy, Microraptor is considered a non-avian dinosaur, and is thus placed in the group of dinosaurs called dromaeosaurs, which includes the ferocious Velociraptor.

Study co-author Clarke said many questions remain about Microraptor's feathers. For example, "we don't know if [they had] more of a greenish-blue iridescence, or a more purplish iridescence."

(See "Dinosaur True Colors Revealed for First Time.")

Published March 9, 2012

In Fine Feather

Photograph courtesy Mick Ellison

The new findings contradict previous theories that Microraptor was a nocturnal dinosaur. That's because dark, glossy plumage (pictured, a modern bird feather) is not a trait found in existing nocturnal birds.

Modern birds can see wavelengths of light and hues invisible to humans, and it's possible that Microraptor had the same abilities, Clarke added.

"The way we perceive this animal and the way its close relatives would've seen it would be different," she said. "Exactly how different, I don't think we know now, but that would be an interesting question for future research."

Published March 9, 2012

Spotted Dino

Illustration by Xing Lida, National Geographic

Anchiornis, another feathered dinosaur, which lived during the middle Jurassic period—some 40 million years before Microraptor—is shown mid-leap.

A 2010 study that examined melanosomes from Anchiornis fossils suggested the creature had black-and-white spotted wings and rust-colored feathers on its head.

The new Microraptor research will lead to more scientifically correct illustrations of feathered dinosaurs and early birds, Brown University's Carney said. (See "Pictures: Evolution of Dinosaur Art.")

"This study provides yet another addition—iridescence—to the palette that scientists now have available for reconstructing the colors of dinosaur plumage," he said.

Published March 9, 2012

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Image courtesy Chuang Zhao and Lida Xing

Published March 9, 2012