Scientists identify the oldest known animal fossils on Earth

Scientists have used fat molecules to solve a long-standing mystery and have identified an ancient creature as one of the first animals on the planet.

For over 75 years, researchers have struggled to classify Dickinsonia, a particular jellyfish-like creature that lived about 558 million years ago. According to National Geographic, the flat, spongy, oval-shaped organism had multiple rib-shaped segments and could grow to over four feet long.

Dickinsonia belonged to a group of extinct life forms, the Ediacaran biota. It is thought that these creatures, which would have emerged in warm, shallow seas 570 million years ago, would be the first complex multicellular organisms on Earth.

But scientists were unable to determine exactly what Dickinsonia was, classifying them either as fungi, protists, or animals.

Now, an international team of researchers has used modern chemistry to discover striking evidence that Dickinsonia was indeed primitive animals. Their study, published this week in the journal Science, is based on fat.

Researchers at the Australian National University, with help from other institutions, have found Dickinsonia fossils containing significant levels of cholesterol – a hallmark of animal life.

540 million years ago, Dickinsonia floated around the Cambrian explosion, when an abundance of new and varied life forms like molluscs, worms and sponges appeared in fossils in a relatively short time short.

This is important because the fossil fat molecules of Dickinsonia prove that "animals were plentiful and abundant" on Earth "millions of years earlier than expected," according to Jochen Brocks, one of the authors of the study.

"The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the holy grail of paleontology," Brocks said in a press release.

The problem that had been holding researchers for so long was that Dickinsonia and others Scientists have generally studied creatures by physically analyzing their old prints.

But Ilya Bobrovskiy, a Ph.D. student at Australian National University, he had the intuition that he could extract and analyze biomarkers from a thin layer of organic matter left in fossils Dickinsonia particularly well preserved.

Most of the fossilized rocks of Dickinsonia near Bobrovskiy University in Australia have undergone a tremendous amount of heat, pressure and weathering over the centuries. He traveled to a remote area of ​​northwestern Russia to hunt fossils he needed.

"I took a helicopter to reach this very remote region of the world – where bears and mosquitoes live – where I could find Dickinsonia fossils with still intact organic material," Bobrovskiy said in the statement.

He finally found good candidates for his research on 330-foot cliffs near the White Sea.

"I had to hang ropes at the edge of a cliff and dig enormous blocks of sandstone, throw them away, wash the sandstone and repeat this process until I found the fossils I was looking for", a- he declared.

Bobrovskiy then developed a special technique to test the remains of Dickinsonia for cholesterol.

Brocks said that when Bobrovskiy showed him the test results, he "could not believe it."

"But I also immediately saw the meaning," Brocks said.

The study is based on the assumption that only animals can produce cholesterol, which some scientists believe could be refuted because more research is being conducted on the first inhabitants of the Earth.