June 12, 2013
Fossil X-Rays Determine Archaeopteryx Had Bright Plumage
Brett Smith for redOrbit.com - Your Universe Online
The ℠dino-bird´ Archaeopteryx has long fascinated paleontologists and a new study in the Journal of Analytical Atomic Spectrometry suggests that the animal had bright plumage and wasn´t all-black as previously thought.
Using a series of cutting-edge X-ray experiments, a team led by researchers from the University of Manchester found chemical traces of pigments in a 150 million-year-old fossil of the early bird.
“This is a big leap forward in our understanding of the evolution of plumage and also the preservation of feathers,” said lead author Phil Manning, a paleontologist with the University of Manchester.
Two recently developed methods have allowed scientists to reach conclusions about the Archaeopteryx plumage.
Last year, a team led by researchers at Brown University performed an analysis of melanosomes, microscopic 'paint pot' structures containing pigment, in an Archaeopteryx feather specimen. That analysis showed that the feather was black.
The Brown University team also identified the feather as a type of feather that covers the primary and secondary wing feathers, referred to as a covert. They suggested that its heavy pigmentation may have helped the bird resist the wear and tear of flight, which is seen in modern birds.
However, that study only analyzed a few locations in the fossilized feather, noted Uwe Bergmann — co-author of the latest study.
"It's actually quite a beautiful paper," said Bergmann, a scientist at the SLAC National Accelerator Laboratory in Menlo Park, California, "but they took just tiny samples of the feather, not the whole thing."
The second recently developed method involved rapidly scanning the entire fossil and analyzing its chemistry with X-ray technology at Bergmann´s facility.
Over the past three years, the team used this method to discover residual chemicals left by the Archaeopteryx specimen in the rock and pigments from the fossilized feathers. Using this method, the team was able to recreate the plumage pattern of the early bird.
Manning noted that the preservation of these compounds in the rock for 150 million years was astonishing.
"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,” he added.
The chemical traces found at the Menlo Park facility show that the Archaeopteryx feather was light in color, with sections of darker pigmentation along one edge and on the tip. Scans of a second fossilized Archaeopteryx confirmed that pigmentation pattern, Manning said.
Just 11 specimens of Archaeopteryx have been discovered so far, the first one being only a single feather. Until recently, researchers thought the entire original animal had been replaced by minerals during fossilization, leaving no chemical evidence behind.
Archaeopteryx is considered a transitional species between dinosaurs and birds. Most paleontologists believe birds derived from theropods, a group of carnivorous dinosaurs that includes the Tyrannosaurus rex.
(Image Below) Caption: This is an artist's illustration of how Archaeopteryx may have looked sporting its new pigmentation. Credit: Courtesy University of Manchester