Chemistry in colour
It boasts more than just beautiful impressions of long-gone feathers. One of the worldās most famous fossils ā of the earliest known bird, Archaeopteryx ā also contains remnants of the feathersā soft tissue.
āItās amazing that that chemistry is preserved after 150 million years,ā says , a geochemist at the University of Manchester, UK. Wogelius and colleagues scanned the āThermopolis specimenā using a powerful X-ray beam from a synchrotron at the in California.
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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 phosphorus along the main shaft of the feathers in the fossil: palaeontologists had long thought that only impressions remained.
āThere is soft-tissue chemistry preserved in places that people didnāt expect it,ā says Wogelius.
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