February 4, 2010 | 1
Last week, researchers announced that they had been able to place, for the first time, original colors on a dinosaur—painting in striking stripes on Sinosauropteryx‘s tail based on new evidence of pigment particles. Today, another team reports that they have decoded the colors of a different dino from head to tail.
The findings, which will be published February 5 in Science, paint a detailed picture of birdlike Anchiornis huxleyi, which has been extinct for some 150 million years and was first described in December 2008.
To establish this dinosaur’s overall coloration, the researchers, led by Quanguo Li of the Beijing Museum of Natural History, studied 29 feather samples under a scanning electron microscope. And what they found was quite a dramatic little dinosaur.
"This was no crow or sparrow, but a creature with a very notable plumage," Richard Prum, a professor of ornithology, ecology and evolutionary biology at Yale University, said in a prepared statement. Nevertheless, the coloring isn’t fully unfamiliar. Quite to the contrary, as the authors noted in the study, it is "strikingly similar to various living birds including domesticated fowl."
Such patterning provides new clues about how these dinosaurs lived. With it, "we can say a lot more about their biology," Jakob Vinther, a graduate student at Yale and coauthor of the new study, said in an interview with ScientificAmerican.com last week.
Researchers haven’t glimpsed the actual Jurassic period colors in either Sinosauropteryx or A. huxleyi. "If you look at these dinosaurs, they don’t look red in the fossil," Vinther explained. Under microscopes though, scientists can see the fossilized shapes of melanosomes, organelles that provide pigment via melanin. These variously shaped particles still give many modern animals their colors and have changed little in the intervening eons, so researchers can use the shapes to deduce what hue they would have provided to ancient feathers.
The find ruffles the feathers of a hypothesis that plumage evolved purely for flight. "This means a color-patterning function—for example, camouflage or display—must have had a key role in the early evolution of feathers in dinosaurs," Julia Clarke, an associate professor of paleontology at the University of Texas at Austin, said in a prepared statement.
Prum calls this new head-to-tail portrait "the ultimate dream of every kid who was ever obsessed with dinosaurs." And there will be plenty of coloring to do, indeed—paleontologists are turning up more feathered dinosaurs each year.
Reconstruction of A. huxleyi in full-color plumage courtesy of Michael A. Digiorgio; image of fossil specimen from which feathers were studied courtesy of J. Vinther/Beijing Museum of Natural History