Chemical link between birds, dinosaurs 'revealed'

Using an X-ray, an international team has revealed this transformative glimpse into one of the most important fossils ever discovered -- the Archaeopteryx, a half-dinosaur/ half-bird species.

"Archaeopteryx is to paleontology what Tutankhamen is to archaeology. It's simply one of the icons of our field. You would think after 150 years of study, we'd know everything we need to know about this animal. But guess what -- we were wrong,"said team member Phil Manning of Manchester University.

Like the other Archaeopteryx specimens, this fossil has undergone extensive visual analyses and even CT scans in the past, none of which revealed that beneath the surface hid the dinobird's chemical remains.

By recording how the X-rays interacted with the fossil, the palaeontologists were able to identify very precisely the locations of chemical elements hidden within. From this, they created the first maps of the dinobird's chemistry, revealing half a dozen chemical elements that were actually part of the living animal itself.

In almost every element studied, the researchers found significantly different concentrations in the fossil than in the rock that surrounds it, confirming that the observed elements are indeed remnants of the dinobird and not merely chemicals that leached from the surrounding rock into fossil.

"People have never used a technique this sensitive on Archaeopteryx before. Because the X-ray beam is so bright, we were able to see the teeniest chemical traces that nobody thought were there," said team member Uwe Bergmann.

The chemical maps, published in the 'Proceedings of National Academy of Sciences', show that portions of feathers are not merely impressions of long-decomposed organic material but actual fossilized feathers that contain phosphorous and sulfur, elements that comprise modern bird feathers.

Trace amounts of copper and zinc were also found in the dinobird's bones, like birds today, the Archaeopteryx may have required these elements to stay healthy.
"We talk about the physical link between birds and dinosaurs, and now we have found a chemical link between them," said University of Manchester geochemist Roy Wogelius, corresponding author on the paper.

"In the fields of paleontology and geology, people have studied bones for decades. But this whole idea of the preservation of trace metals and the chemical remains of soft tissue is quite exciting," he added.