The Dickinsonia fossil solves the global paleontological mystery of 558 million years

The oldest animal in the world, which lived 558 million years ago in Russia, was identified for the first time.

The scientists realized that the specimen was an animal after finding that it contained traces of cholesterol, a type of fat characteristic of animal life.

The strange and relatively flat body has lived 20 million years before the "Cambrian explosion" of animal life, according to the Daily Mail.

Scientists have described the discovery of the fossil, which looks like a cross between a leaf and a thumbprint, like the "holy grail" of paleontology.

The bizarre marine creature, named Dickinsonia, was nearly four and a half meters long (1.4 meters), and almost as wide.

Professor Jochen Brocks, Principal Investigator at the Australian National University of Canberra, said, "The creature actually produces cholesterol, which is the hallmark of animals, and tells us that it is actually our first ancestor." .

The animal was oval-shaped with segments similar to veins along its body.

He lived during the Ediacaran period which lasted nearly 100 million years before the start of the Cambrian period.

The "Cambrian explosion" took place when complex animals and other macroscopic organisms – such as molluscs, worms, arthropods and sponges – began to dominate the fossil record.

We did not know if they were actually animals – so far, the authors wrote in the article published in Science.

"The fossil fat molecules we found prove that animals were large and abundant 558 million years ago, millions of years earlier than expected," said Professor Brocks, a scientist. of the earth.

The fossil was dug up by doctoral student Ilya Bobrovskiy in a remote area of ​​the White Sea coast in northwestern Russia.

"Scientists have been fighting for over 75 years on what Dickinsonia and other bizarre fossils of Edicaran biota were: unicellular giant amoebae, lichens, failed evolutionary experiments or the first animals on Earth" said Professor Brocks.

"The fossil fat now confirms that Dickinsonia is the oldest known animal fossil, solving a decades-old mystery that has been the holy grail of paleontology."

Mr. Bobrovskiy said the team had developed a new approach to study the Dickinsonia fossils, which hold the key between the old world dominated by bacteria and the world of large animals that appeared 540 million years ago. of the Cambrian explosion.

He said: "The problem we had to solve was to find Dickinsonia fossils that kept organic matter.

"Most of the rocks containing these fossils, such as those in the Ediacara Hills in Australia, have been subjected to a lot of heat, a lot of pressure, and have been altered – the rocks that paleontologists have studied for decades, which is why they were stuck on the question of Dickinsonia's true identity. "

Palaeontologists normally study the structure of fossils, but Mr Bobrovskiy extracted and analyzed molecules from inside the Dickinsonia fossil found in ancient rocks in Russia to make a decisive discovery.

He explained: "I took a helicopter to reach this very remote area of ​​the world – where bears and mosquitoes live – where I could find Dickinsonia fossils whose organic matter was still intact.

"These fossils were located in the middle of the cliffs of the White Sea, which are between 60 and 100 meters high.

"I had to hang the edge of a cliff on ropes and dig huge blocks of sandstone, throw them on the ground, wash the sandstone and repeat this process until I found the fossils I was looking for. "

Professor Brocks said that studying molecules from these ancient organisms could change the game.

He said, "When Ilya showed me the results, I just could not believe it, but I immediately saw the meaning."

His international team included colleagues from the Russian Academy of Sciences and the Max Planck Institute of Biogeochemistry and the University of Bremen in Germany.