X-ray of Plumage (IMAGE) DOE/SLAC National Accelerator Laboratory Caption Researchers report today in Science Express that they have taken a big step in determining what the first birds looked like more than 100 million years ago, when their relatives, the dinosaurs, still ruled the Earth. At the Department of Energy’s SLAC National Accelerator Laboratory, they discovered chemical traces of a pigment, an important component of color, that once formed patterns in the feathers of the fossilized birds. Pictured here is a synchrotron rapid scanning x-ray fluorescence image of the calcium distribution in a fossil specimen of Confuciusornis sanctus, an ~120 million year old avian species, the oldest documented to display a fully derived beak. Calcium is high in the bones as shown by the bright white areas, but calcium is also high in the areas corresponding to residue of downy feathers in the neck region. This is interpreted to be due to the distribution of calcium being controlled by eumelanin chelates in the neck feathers, indicating that these soft tissues were originally darkly pigmented. Credit Data were collected at SLAC's Stanford Synchrotron Radiation Lightsource, image created by Gregory Stewart (SLAC). Usage Restrictions Credit where possible. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.