Soft tissue remnants discovered in Archaeopteryx fossil

20:00 10 May 2010 by Jeff Hecht
For similar stories, visit the Dinosaurs Topic Guide

Chemistry in colour (Image: W. I. Sellers/Stanford Synchrotron Radiation Lightsource)

It boasts more than just beautiful impressions of long-gone feathers. One of the world's most famous fossils – of the earliest known bird, Archaeopteryx – also contains remnants of the feathers' soft tissue.

"It's amazing that that chemistry is preserved after 150 million years," says Roy Wogelius, a geochemist at the University of Manchester, UK. Wogelius and colleagues scanned the "Thermopolis specimen" using a powerful X-ray beam from a synchrotron at the Stanford Synchrotron Radiation Lightsource in California.

The synchrotron excites atoms in target materials to emit X rays at characteristic wavelengths. The scan reveals the distribution of elements throughout the fossil. The green glow of the bones in this false-colour image shows that Archaeopteryx, like modern birds, concentrated zinc in its bones. The red of the rocks comes from calcium in the limestone that had encased the fossil since the animal died.

Copper and zinc are key nutrients for living birds, and their presence in the fossil bones shows the evolutionary link with dinosaurs. The study also revealed phosphorous along the main shaft of the feathers in the fossil: palaeontologists had long thought that only impressions remained.

"There is soft-tissue chemistry preserved in places that people didn't expect it," says Wogelius.

The whole dinobird. Scale bar = 10 centimetres (Image: W. I. Sellers/Stanford Synchrotron Radiation Lightsource)