Ancient ‘feathered dragon’ bird’s tail was twice the length of its body

By Stephen Beech

An ancient bird dubbed the "feathered dragon" had some of the longest tail feathers ever found on a fossil.

The newly discovered species displayed its "crazy" tail feathers to attract mates around 120 million years ago, say scientists.

The bird measured just 15 centimeters (5.9 inches) from beak to tail, but its twin tail feathers were nearly 30 centimeters (11.8 inches) long.

The new fossil discovery shows that birds' over-the-top ornamentation dates back to the time of the dinosaurs, according to a study published in the journal PLOS One.

The American research team say the new species of fossil bird, recently discovered in Liaoning, China, had tail feathers twice as long as its body.

It was named Plumadraco, meaning feathered dragon.

Study lead author Alex Clark, a PhD candidate at the University of Chicago, said: "Plumadraco was the size of an American robin, but its tail feathers were about a foot long, twice the length of its body.

"They're some of the proportionally longest tail feathers ever found in a fossil bird."

He explained that birds are the only members of the dinosaur family that didn't die out from the effects of an asteroid hitting Earth 66 million years ago.

But only one group of dinosaur-birds survived the asteroid strike.

The most diverse group of birds alive at the time, the enantiornithines, all died out alongside the non-bird dinosaurs.

Plumadraco lived about 121 million years ago during the Cretaceous Period, well before the big extinction event, but it was part of the enantiornithine group of birds.

Clark came across the fossil on a research trip to China's Shandong Tianyu Museum of Nature with his advisor and co-author Jingmai O'Connor, curator of the Field Museum in Chicago.

As he perused hundreds of fossil birds, one in particular caught his eye.

Clark said: "I saw this little guy, and I did a double-take when I saw the tail feathers.

"I'm really interested in the way birds do displays to attract mates, and I thought that these tail feathers were so crazy, they had to be used for something like that."

Clark and his colleagues analyzed the fossil, comparing it to other enantiornithine birds, and determined that it was a new species to science.

He named it Plumadraco bankoorum — "Banko's feathered dragon" — in honor of the father and son team Winston and Paul Banko, who have dedicated decades to studying and protecting living birds.

Clark's examination of Plumadraco has yielded several theories about what the ancient bird was like in life.

He says the length of the tail feathers indicate that the specimens identified in the study were probably males.

Clark said: "There are many examples of both male and female modern birds with long, showy feathers, but there seems to be this certain threshold where, if feathers reach a certain proportional length, then it tends to be a trait that males have developed in order to attract females.

"Plus, the fossils of some other enantiornithine birds show remnants of muscle tissue along the tail region, and based on those muscles, birds like Plumadraco would have had pretty limited movement for their tails.

"However, they could pump their tail feathers up and down, and that's a behavior that we see across birds today that do courtship displays only in males."

The stiff spines at the center of Plumadraco's tail feathers, and the tapered shape ending with a rounded tip, suggest that males would raise their tail feathers, and the ends of those feathers would move back and forth in a sort of "flickering" motion.

The team also learned about the color of Plumadraco's tail feathers.

Using a handheld mass spectrometer, a chemical instrument that looks similar to a ray gun, they analyzed the chemical makeup of the fossil.

Based on the concentrations of different chemicals present, the researchers say Plumadraco's feathers were probably dark brown, or black.

They believe it's possible that there was some sort of "eye-catching" color at the tips of its tail feathers — maybe something iridescent or blue, since those colors are produced by the structure of the cells rather than by the pigments whose chemical signatures were measured in the study.

The researchers say the new insights into Plumadraco's physiology and behavior help scientists better understand birds today.

Clark said: "This fossil, maybe more than any other fossil bird that's ever been discovered, shows that birds have been evolving costly, elongate, specialized features to attract mates for a long, long time.

"Based on these fossils, female choice in selecting ornamented males has been playing a huge part in how birds look and behave for more than 120 million years."

He added: "Working with fossil birds like Plumadraco continues to personally demonstrate to me that life is far more complex and richer than what we thought previously.

"To know that at one point in time, about 121 million years ago, this very individual flew through the dawn light with these incredible tail feathers streaming behind it is truly something to marvel.

"Even millions of years after its death, we can still appreciate just how spectacular this species would have looked like in life."