The soft outer skeletons are not well preserved – with the exception of some exceptional sites around the world. There is a wonderful spot in the south of France, where the fossils of spiders that weaved a web 22.5 million years ago were discovered.
Scientists said they have identified why many soft-bodied creatures such as spiders, insects and fish are buried and preserved. With such details in this particular rock formation in Aix-en-Provence. Very favorable conditions include a substance produced by microalgae that would envelop the spider and promote a protective chemical change.
“Most life doesn’t turn into a fossil,” Alison Olcott, associate professor of geology and director of the University of Kansas Research Center, said in a news release.
“It’s hard to become a fossil. You have to die under very specific conditions, and one of the easiest ways to become a fossil is to have hard parts like bones, horns and teeth. So, our record of the life of a thin, terrestrial body is,” said Olcott, lead author of the study published in Communications Earth and Environment Magazine, Life is like spiders choppy.
“But we have these exceptional preservation periods when all conditions were in harmony in order for the preservation to occur.”
Fluorescence provides clues
In the statement, Olcott said the discovery came thanks to the decision to examine the spider’s fossil under a fluorescent microscope. This type of observation is not part of the standard protocol for examining fossils, but research The team thought it might help them discern more details of the fossilized spiders, which blended in with the surrounding rocks. Different elements in the rock absorb the energy of UV light in a microscope and transform light at different wavelengths.
“To our surprise it glowed, and so we became very interested in what the chemistry of these fossils made them glow. If you look at the fossil on the rock, it is almost indistinguishable from the rock itself, but it glows a different color in the fluorescent range.”
“Not every geological sample is self-radiant and glowing – but when it is, it can be amazing and yield a lot of information, Olcott said. Microscopic aquatic algae detected by fluorescence microscopy are known as diatom fossils, and when alive they secrete sulfur-rich substances that form algal mats.
“These microalgae make the sticky, sticky ball — that’s how they stick together,” she said.
The authors suggested that this substance coated the spiders and promoted a process called sulfur, which stabilizes and preserves the spiders’ fragile bodies.
“Basically, the chemistry of microalgae and the chemistry of spiders work together to achieve this unique conservation,” she said.
Olcott said the discovery could help geologists locate other exceptional fossils from this time period in other parts of the globe.
“If diatom mats help bring about this remarkable preservation of fossils, we should be able to explore more units of diatomite, the diatom-rich rocks that exist globally at this time, to look for more of these deposits.
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