[Animals] What is the oldest animal found on Earth?

[#Wittels-]

It lived 558 million years ago and was about 1.4 meters long.

A strange creature called Dickinsonia, which grew to about 1.4 meters in length and was oval in shape with rib-shaped segments on its body, is the first recorded animal on Earth. It lived 558 million years ago, according to traces of cholesterol found in a well-preserved ancient fossil.

An Australian National University (ANU) doctoral student, Ilya Bobrovskiy, discovered in 2018 a well-preserved fossil of an enigmatic organism called Dickinsonia in a remote area near the White Sea in northwestern Australia. Russia . The tissue of these remains still contains cholesterol molecules, a type of fat that is a hallmark of animal life.

 

A team of scientists led by the ANU was able to conclude, thanks to the analysis of these fat molecules, that this example is the first confirmed animal in the geological record, since it lived on Earth no less than 558 million years ago.

The principal investigator of the study then published in the journal Science, Associate Professor Jochen Brocks, explained that the Cambrian explosion happened when complex animals and other macroscopic organisms, such as mollusks, worms, arthropods and sponges, began to dominate the fossil record. "The fossil fat molecules we have found show that animals were already large and abundant 558 million years ago, much earlier than previously thought," he added.

This was part of the organism of the Ediacara biota, made up of the first living beings that po[CENSORED]ted the Earth 20 million years before the Cambrian explosion of animal life occurred.

Some specimens found measure almost a meter and a half in length, but the most common is that they measure much less: a few tens of centimeters.

 

The 'Holy Grail' of paleontology
"Scientists have been researching Dickinsonia and other strange fossils from the Ediacaran biota for more than 75 years. Fossil fat now confirms Dickinsonia as the oldest known animal, solving a decades-old mystery that has been the 'Holy Grail' of paleontology", noted.

Its discoverer, Bobrovskiy, points out that the team came up with a new approach to study these fossils, which hold the key to the passage between the old world dominated by bacteria and the world of large animals that emerged 540 million years ago during the Cambrian explosion. .

"The problem we had to overcome was finding Dickinsonia fossils that would have retained some organic matter," said the scientist.

 

 

Most of the rocks that contain these fossils, like those in the Ediacara Hills in Australia, have withstood a lot of heat, pressure, and erosion. Paleontologists have been studying them for decades, which explains why they were stuck on the true identity of Dickinsonia.

Climb a cliff to find the remains

 

Paleontologists normally study the structure of fossils, but Bobrovskiy extracted and analyzed the molecules inside them. "I took a helicopter to this remote part of the world, home to bears and mosquitoes, where I was able to find Dickinsonia fossils with organic matter still intact," he said.

These fossils were in the middle of the cliffs of the White Sea, which are between 60 and 100 meters high. "I had to hang from the edge of a cliff with ropes and excavate huge blocks of sandstone, throw them down, wash the stone and repeat this process until I found the fossils I was looking for," Bobrovskiy explained.

 

For Brocks, being able to study the molecules of these ancient organisms is revolutionary. "When Ilya showed me the results, I just couldn't believe it. But I also immediately understood its importance," he says.

ANU led the research in collaboration with scientists from the Russian Academy of Sciences and the Max Planck Institute for Biogeochemistry and the University of Bremen in Germany.

 

Link: https://www.informacion.es/medio-ambiente/2022/02/08/animal-antiguo-hallado-tierra-62458272.html