The first complete chemical analysis of feathers from the Archaeopteryx, a fossil linking dinosaurs and birds, reveals its plumage consisted of a light color with a dark edge and tip rather than all black, as previously believed.

The findings, published in the Journal of Analytical Atomic Spectrometry, represent a “big leap forward in our understanding of the evolution of plumage and also the preservation of feathers,” paleontologist and lead author Phil Manning said in a press release.

The discovery was made through a series of X-ray experiments performed by a team from The University of Manchester as well as scientists from the U.S. Department of Energy’s SLAC National Accelerator Laboratory.

Through their testing, the researchers were able to find chemical traces of the original “dinobird” and dilute traces of plumage pigments in the 150 million-year-old fossil. (Archaeoptheryx may be the "original," but a recently described, even older speices of ancient bird dethroned Archaeoptheryx from its seat as the oldest bird.) 

Currently, there are only 11 known specimens of Archaeopteryx, one of which consists of a single feather. Furthermore, up until just a few years ago, researchers thought minerals had long replaced all the bones and tissues of the original animal during fossilization, leaving no chemical traces behind; however, two new methods have since exposed more information about the dinobird and its plumage.

The first discovery was that of melanosomes, microscopic “biological paint pot” structures in which pigment was once made, but are still visible in some rare fossil feathers.

A team led by researchers at Brown University announced last year that an analysis of melanosomes in a single Archaeoptheryx feather indicated it was black. Additionally, they identified the feather as a covert, or one that covers the primary and secondary wing feathers, and that its heavy pigmentation may have strengthened it against the wear and tear of flight, as seen in today’s birds.

However, the study had one significant drawback: it only examined melanosomes in a few locations in the fossilized feather.

The second method is one developed by both Manning and Roy Wogelius, also based in Machenster’s School of Earth, Atmosphere and Environmental Sciences, and revolves around rapidly scanning entire fossils and analyzing their chemistry with an X-ray beam at SLAC’s Stanford Synchrotron Radioation Lightsource located in the United States.

Over the past three years, the team used this second method to uncover those chemical traces locked in the dinobird’s bones, feathers and in the surrounding rock, in addition to pigments from the fossilized feathers of two specimens of another species of early bird.

Doing this, the scientists said, was what enabled them to recreate the plumage pattern of the extinct bird for the very first time.

“The fact that these compounds have been preserved in-place for 150 million years is extraordinary,” Manning said.

Furthermore, the scientist explained, scans of a second fossilized Archaeopteryx -- the "Berlin counterpart" -- suggest it had the same plumage pigmentation pattern as well, solidifying, in the minds of the researchers, their findings.

“This work refines our understanding of pigment patterning in perhaps the most important known fossil,” Wogelius said. “Our technique shows that complex patterns were present even at the very earliest steps in the evolution of birds.”

In addition, the team’s results demonstrate the importance of a chemical analysis produced by synchrotron X-ray sources when studying fossil remains.

Going forward, the discovery of the Archaeopteryx’s plumage patterns can help researchers start to study their possible role in courtship, reproduction and evolution as well as possibly shed new light on their health, eating habits and environment.

“It is remarkable that X-rays brighter than a million suns can shed new light on our understanding of the processes that have locked elements in place for such vast periods of time,” Manning said. “Ultimately, this research might help inform scientists on the mechanisms acting during long-term burial, from animal remains to hazardous waste. The fossil record has potential to provide the experimental hindsight required in such studies.”