Scientists Map Organic Compounds From “˜Dino-Mummy’
Scientists have mapped organic compounds that are still surviving in a 50-million-year-old sample of reptile skin.
The infrared picture reveals the chemical profile of the skin, which offers an insight into how it was preserved.
The scientists say that the sample was so well preserved that it was hard to determine the difference between the fossil and the fresh samples.
They reported their findings in the journal Proceedings of the Royal Society B.
"It is a relatively new technique – I think we are the first people to apply it to paleontology," said co-author Roy Wogelius, a geochemist from the University of Manchester, UK.
He told BBC that the technology allows non-destructive analysis, meaning that it could be used on rare museum specimens.
"Now we can apply this organic technique [it] means that there is an awful lot of material that we can analyze in ways people did not realize were possible."
Wogelius said that possible specimens could include invertebrates, marine creatures and plant material.
He said that the infrared mapping technique worked similar to a record player.
"What you do is you take something that transmits light, so if you take a very small needle – about the size of an old phonograph stylus – and make it so it can transmit light," he told BBC.
"You can shine light down through the needle and then when the needle is in contact with the specimen’s surface, a little of that light will be absorbed – that is the signal that we use."
"When there is a little more absorption at a certain frequency, that is a fingerprint for a particular organic compound."
Wogelius said the team of U.K. and U.S. researchers attempted to use the technology before on a sample from a "dino-mummy," which is a 67-million-year-old fossil that still had much of its soft tissue intact.
"This was one of the best preserved dinosaurs discovered, and we were able to show that there was organic compound from the skin remaining (on the fossil)," he told BBC.
"The problem was that the (sample) fell apart so easily, we could not map anything. So while we were confident that what we had was skin residue, we just could not see if there was any biological structure there."
Wogelius said the preservation of the latest sample was both remarkable and solid.
"It was also flat which made it very, very convenient to map it," he added.
"So we took this new technology… and the detail of what we were able to reveal was quite striking."
The team used infrared techniques that were able to confirm that soft tissue was present on the fossil.
They were able to offer a hypothesis on how the tissue survived for 50 million years.
The details from the study suggest that when skin’s organic compounds began to break down, they formed a chemical bond with trace metals that go on to build a "bridge" with the surrounding minerals.
The skin and remaining soft tissue was protected from further decomposition or further erosion.
"These new infrared and X-ray methods reveal intricate chemical patterns that have been overlooked by traditional methods for decades," Wogelius told BBC.
"We have learned that some of these compounds, if the chemistry is just right, can give us a bit of a whiff of the chemistry of these ancient organisms."
He said the team’s findings offered an insight into a number of areas.
"By doing the infrared analysis, we get some detail about the soft tissue that remains," he said.
"In fact, the chemical remains – in terms of the organic compounds – very closely resemble what we get when we look at modern gecko skin. That means that some of the organic components have been conserved over that period of time.
"Some of the trace metal chemistry is also original to the organism, and that give us hope in terms of understanding some bio-metallic complexes, in particular understanding the coloration and pigmentation of the skin.
"It is very exciting because we can start to pull out more detail."
Wogelius said that this sort of information could help find a better understanding of a range of research avenues.
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Image Caption: Optical photographs of BHI-102B. (a) Single lens reflex image showing the exceptional preservation of the scale pattern, black box shows area magnified in next image, (b) magnified reflected light mosaic illustrating the preserved skin detail at the base of the tail, white box represents area mapped by FTIR.
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