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Home / Science / The creation of "synthetic" fossils in the laboratory provides information about fossilization processes

The creation of "synthetic" fossils in the laboratory provides information about fossilization processes



Experimental samples compared to fossils except for the microscopic structure of melanosomes. Credit: Fossil Lizard Images courtesy of Nicholas Edwards and Wang Yuan.

A newly published protocol, involving scientists from the University of Bristol, could change the way fossilization is studied.

In addition to the direct study of fossils themselves, experimental treatments of fresh organic remains can be used to study fossilization.

A commonly used experimental approach is so-called artificial maturation, where high heat and high pressure accelerate the chemical degradation reactions that normally occur over millions of years, when a fossil is buried deep underground and the geothermal heat and pressure above it exposed sediment.

Maturation is a major component of organic geochemists who want to study the formation of fossil fuels, much like the more intense experimental conditions that produce synthetic diamonds.

More recently, maturation has been used to study the formation of exceptional fossils containing soft tissues as dark, organic films in addition to mineralized tissues such as bone, including fossil dinosaurs, with organically preserved feathers.

However, much maturation equipment is often limited by the use of small, sealed chambers that trap not only the highly stable organic molecules of interest to paleontologists and organic geochemists, but also the degradation products of less stable molecules that are less likely to be retained in fossils , Therefore, direct comparisons between the experiments and the fossils are complicated.

For example, as Evan Saitta, who recently completed his Ph.D. at the University of Bristol in the School of Earth Sciences and is now a postdoctoral fellow at the Field Museum of Natural History in Chicago, led this more traditional maturation experiments on feathers during his MSc (also in Bristol), the result was a foul-smelling liquid

Jakob Vinther, Lecturer at Bristol School of Earth Sciences and School of Biological Sciences and Saittas Ph.D. and MSc consultant, added: "What we are seeing is that fossils are not simply a result of how fast they rot, but rather the molecular composition of different tissues, but it is inherently difficult, the conceptual leap understanding to make chemical stability to understand how tissues and organs can survive or not. "

Saitta said," At the end of my MSc I became a bit ambitious. "If maturation was known as a useful simulation of fossilization processes, I then, these experiments could only produce "synthetic" fossils on sediment-packed samples, and fossils form in sedimentary rocks, which can be porous and allow the escape of fugitive degradation products. "

Then, Saitta teamed up with Tom Kaye of the Foundation for Scientific Advancement, who provided the technical experience to make the idea a reality.

Kaye said, "My lab is constantly dealing with high pressure equipment, we had simulated the ability y of the compressing matrix around the samples, which was the game changer, to funeral, and our next step is to expand the system to large copies." [1

9659005] As the researchers described in their recent work published this week in the journal Palaeontology the results did not disappoint.

Saitta explains, "The sediment acts like a filter that allows unstable molecules to escape from the sample and recognize brown, flattened bones surrounded by dark organic layers that once contained soft tissue. [19659016] "These results are similar to extraordinary fossils, not just visually. but also microscopically, as shown using a scanning electron microscope. "

Microscopic pigment-carrying structures called melanosomes reside within the organic films in feathers and lizards treated with the new method, while unstable proteins and adipose tissue are degraded and lost in exceptional fossils used by scientists such as Vinther to reconstruct the original colors of dinosaurs.

Preliminary tests on leaves and beetles are also comparable. They are comparable to their fossil equivalents, and tree resin can even be hardened similar to fossil copal or amber. [Theresearcherssaythatthenewmethodofsedimentfiltrationrepresentsanimprovementoverpreviousmaturationexperimentsandwillallowmanyteststohypothesizeorganicpreservationinfossilsandsediments

Future additions to the protocol will address other aspects of fossilization than the Sim include the heat and pressure of depth burial.


Further information:
Dinosaur blood? New research urges caution in fossil soft tissue

Further information:
"Sediment-Enriched Maturation: A Novel Method for Simulation of Diagenesis in Organic Fossil Preservation" E. Saitta, T. Kaye, and J. Vinther, Paleontology 2018.

Sources in Journal:
paleontology

Provided by:
University of Bristol


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