True-Color Dinosaur Pictures: First Full-Body Rendering

Fossil Feathers Behind Breakthrough

Photograph by Jakob Vinther

In the Beijing Museum of Natural History, the team behind the new study in Science, co-led by Yale University's Jakob Vinther, found an Anchiornis skeleton (pictured) preserved in an ochre-colored slab of mudstone.

With fossilized "protofeathers" bursting from the bones in every direction—and faint evidence of dark and light markings—the fossil was an ideal target for researchers seeking prehistoric melanosomes,pigment-bearing organelles within feathers.

The microscopic particles were first found preserved in a fossil—in this case, a prehistoric bird—by Vinther and his team in 2008. The particles had previously been interpreted in fossils as bacteria.

In modern birds, different types of melanosomes are known to produce different colors in feathers. Eumelanosomes are rodlike and are associated with the colors black and gray. Phaeomelanosomes are round and produce colors ranging from reddish brown to yellow. A lack of melanosomes makes white.

February 4, 2010

Crown of Color

Illustration courtesy Michael DiGiorgio, Yale

The subject of the February 4, 2010, Science study—the 155-million-year-old Anchiornis huxleyi—turns out to have looked something like a woodpecker the size of a chicken, with black-and-white spangled wings and a rusty red crown.

Only a short time ago Anchiornis was completely unknown to science. The chicken-size dinosaur species' color patterns were decoded after the study authors had used a scanning electron microscope to study pigment samples taken from fossil feathers all over a specimen and then compared the samples to pigment from modern birds.

(Pictures: Evolution of Dinosaur Art.)

February 4, 2010

Sexy Beast?

Illustration courtesy Michael DiGiorgio, Yale

Anchiornis's complicated pattern of reddish brown, black, gray, and white feathers may have been useful in attracting mates or some form of visual communication, as is often the case in living birds, researchers speculate.

The new find's implications for the evolution of feathering and flight are "striking," said study co-author Julia Clarke, a vertebrate paleontologist at the University of Texas in Austin.

Anchiornis shows that, "when elongate feathers first appear [in the fossil record], they are already distinctively spotted and striped," Clarke said. "We now have patterns within individual feathers in dinosaurs long before we get some kind of aerial locomotion."

Ornithologist Richard Prum of Yale University added that "a more likely function"—other than flight—"for both the crown and limb feathers of Anchiornis is communication or signaling.

"This could have been in lots of contexts, including sexual display, territoriality, et cetera," Prum said. "It could also have been like modern redstarts, which use their bright wing and tail patches to scare up insects, which [the birds] then seize in flight."

February 4, 2010

Barnyard Dinosaur?

Photograph by Joel Sartore, National Geographic Stock.

The color patterns on Anchiornis's limbs are "quite similar to the silver-spangled Hamburg chicken [pictured], a domestic breed of ornamental chicken," said ornithologist Richard Prum of Yale University. Prum is a co-author of the new study and has received funding from the Committee for Research and Exploration of the National Geographic Society (which owns National Geographic News).

"The significance of these finely preserved feathered dinosaurs and early birds is that they pose questions we didn't even know to ask," said study co-author Julia Clarke, a vertebrate paleontologist at the University of Texas in Austin.

"In some ways the story is just opening up, and we can't predict where it is going.

(Quiz: Test your dinosaur IQ.)

February 4, 2010