Over the past couple decades paleontologists have come to realize that many dinosaurs bore colorful coats of feathers, rather than just the drab leathery hides with which we’re all familiar. Animals like Archaeopteryx, an ancient species that existed in that weird space between dinosaur and modern birds, showed early evidence of fossil feathers, and over time that evidence base grew and grew.
During these early days, artists’ renditions of what these increasingly-feathered dinosaurs looked like were filled with a healthy dose of speculation, but in 2010, much of that guessing was stripped away. Three years ago, says National Geographic, scientists unveiled a technique to accurately reproduce the colors of dinosaurs’ feathers. Then, the race was on, as species after species had their colors reproduced.
But, says Ed Yong in Nature, paleontologists’ palette may have been wrong all along. To make the color reproductions, scientists look at the shape, size and distribution of tiny pigment-bearing organs found in the fossil feathers. A new study led by Maria McNamara, however, discovered that fossilization changes these organs, squishing them over time.
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“McNamara and her colleagues mimicked the process of fossilization by placing modern bird feathers in an autoclave — a machine that sterilizes lab equipment with 250 times atmospheric pressure and temperatures of 200–250 °C. “A brief spell in an autoclave can reasonably simulate the effects of temperature and pressure during burial over millions of years,” she says.
The changed shape means a changed color, and the understanding that coloring reproduced from fossilized feathers may be not quite right. By understanding the pressures and temperatures that affected the fossil, however, McNamara thinks we might be able to reverse-engineer the dinosaurs’ true colors.
Jakob Vinther, a scientist who led the boom in dinosaur-color research, says Yong, doesn’t seem too fussed by the new study. He says the difference in coloration wouldn’t be that noticeable: ‘“It could have an effect if we want to discriminate between a reddish-brown and a slightly less reddish-brown, but we’re not near those sorts of assessments,’ he says.”
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