X-rays reveal Dinobird's patterned plumage

Research published in the Royal Society of Chemistry's Journal of Analytical Atomic Spectroscopy has revealed chemical traces of plumage pigments in fossils of the famous 150-million-year-old 'dinobird'.

Scientists at the University of Manchester used a combination of X-ray spectroscopy techniques to examine three key specimens of Archaeoptryx fossils and found trace-metals that have been shown to be associated with pigment and organic sulphur compounds that can only have come from the animal's original feathers.

Previous research on a fossilised Archaeopteryx feather uncovered melanosomes - microscopic 'biological paint pot' structures in which pigment was once made - which led researchers to believe that the dinobird's plumage was black. However, that study examined melanosomes from just a few locations in the fossilised feather.

The University of Manchester team worked together with colleagues at the US Department of Energy's (DOE) SLAC National Accelerator Laboratory to use a combination of Synchotron Rapid Scanning X-ray Fluorescence (SRS-XRF) and sulphur X-ray Absorption Near Edge Structure (XANES) spectroscopy methods to examine the entire fossil, allowing them to recreate the plumage pattern of the extinct bird for the first time.

Dr Phil Manning, a palaeontologist at The University of Manchester who led the research, said: "The fact that these compounds have been preserved in-place for 15 million years is extraordinary.

"Together, these chemical traces show that the feather was light in colour with areas of darker pigment along one edge and on the tip. Scans of a second fossilised Archaeopteryx, known as the Berlin counterpart, show that the trace-metal inventory supported the same plumage pigmentation pattern."

Co-author Dr Roy Wogelius, also based in Manchester's School of Earth, Atmospheric and Environmental Sciences, said: "This work refines our understanding of pigment patterning in perhaps the most important known fossil. Our technique shows that complex patterns were present even at the very earliest steps in the evolution of birds."

Dr Manning added: "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. 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."