MADELEINE BRAND, host:
If you go into a toy store and look at those little, plastic dinosaurs, you'll see a rainbow of colors: yellow stripes, red armored plates, bright blue wings, all imaginary, some toy company's vision of the past. But now, scientists say they have found evidence from about 125 million years ago of one real dinosaur's color. It's a kind of orange.
NPR's Nell Greenfieldboyce has the story.
NELL GREENFIELDBOYCE: Scientists know a lot about dinosaurs from fossils, but the color of dinosaurs has always been unknowable, at least that's what paleontologist Mike Benton always told his students at the University of Bristol in the United Kingdom.
Professor MIKE BENTON (Earth Sciences, University of Bristol): This was the one point at which we had to give up.
GREENFIELDBOYCE: Because fossils tend to preserve an animal's hard parts, like bones and teeth, and not soft parts like skin.
Recently, though, scientists have discovered a bunch of dinosaurs covered with primitive feathers, and feathers are made of tough proteins.
Prof. BENTON: And, in fact, they can survive even in conditions where other internal organs, you know, muscles and guts and brains and so on, will disappear.
GREENFIELDBOYCE: Unfortunately, these fossilized, ancient feathers just look like rock.
Prof. BENTON: When you look at the feathers, you don't know what the colors were. The feathers are a mixture of brownish colors. They're just preserved either as sort of dirty, whitish, beige kind of color and a kind of darker, equally dirty kind of brownish color.
GREENFIELDBOYCE: Benton and his colleagues wondered if they could get clues about the original color by looking at tiny structures inside the fossilized feathers. After all, they knew that in the feathers of living birds, some color comes from pigments called melanins.
Prof. BENTON: When it goes into a hair or a feather, the melanin is actually contained within a kind of capsule.
GREENFIELDBOYCE: And the shape of the capsule depends on the color.
Prof. BENTON: The black or dark brown kind of melanin goes into a somewhat sausage-shaped capsule.
GREENFIELDBOYCE: While a reddish-brown, ginger kind of melanin goes into a round capsule shaped like a ball. With this in mind, the researchers used a sophisticated, powerful microscope to peer inside primitive feathers on a turkey-sized dinosaur called Sinosauropteryx.
Prof. BENTON: It's a flesh-eater. It's got sharp little teeth in its mouth and it's got grabby little hands. It's a two-legged dinosaur, so very slender limbs. It's got a sort of straightish backbone and a long, thin tail.
GREENFIELDBOYCE: Fossils show that this tail was ringed with dark bands of primitive feathers that look like bristles. And inside these short bristles, Benton and his colleagues found ball-shaped melanin capsules. That's the shape associated with the reddish-brown, ginger color.
Prof. BENTON: These dark stripes, as far as we can tell, were exclusively ginger.
GREENFIELDBOYCE: In between these ginger stripes, he said there probably were white feathers, but these white ones would have had less structural strength and would not have been preserved like the ginger-colored feathers.
Prof. BENTON: And so, this early dinosaur, with its long, thin tail had ginger and white stripes up the tail. For the first time ever, we have evidence, we believe fairly watertight evidence of the original color.
GREENFIELDBOYCE: These results are reported in the journal Nature, and they're incredibly cool and surprising, at least according to Thomas Holtz. He's a paleontologist at the University of Maryland.
Dr. THOMAS HOLTZ (Paleontologist; Department of Geology, University of Maryland): This study begins to bring the colors of dinosaurs out of the realm of artistry and into the realm of science.
GREENFIELDBOYCE: But Holtz says this approach will only be possible for feathers and maybe scales on those dinosaurs that are exceptionally well-preserved in fossils. That doesn't include one he studies - T. Rex.
Dr. HOLTZ: I would love to know if Tyrannosaurus was green or brown or, you know, chartreuse. It's unlikely that I'll ever know or that anyone will ever know the colors of some of our favorite dinosaurs.
GREENFIELDBOYCE: For these extinct creatures, it looks like artists will continue to be limited only by their imagination, not by science.
Nell Greenfieldboyce, NPR News.