Published: Fri, September 21, 2018
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Scientists identify earliest known animal 558 mn years ago

Scientists identify earliest known animal 558 mn years ago

"The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology", Brocks continued.

A fossilised lifeform that existed 558m years ago has been identified as the oldest known animal, according to new research.

The decades-long mystery surrounding a creature that lived on Earth over half a billion years ago has finally been settled, thanks to fossils found in Russian Federation which are so well preserved they still contain fat molecules.

Experts not connected to the study said that evidence is strong, and that most scientists who had studied the matter already believed that Dickinsonia was probably an animal.

In September 2017, British researchers said they were certain it was an animal, based on a study of multiple fossils. They published their results in the journal Science. "The sediments were so fresh that the organic matter of these fossils was still preserved, allowing us to extract the molecules from that tissue".

She said: "Now we know that animal life started before the Cambrian, in the Ediacaran". These organisms predated the "Cambrian explosion" of animal life over the next nine million years.

"Scientists have been fighting for more than 75 years over what Dickinsonia and other freaky fossils of the Ediacaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution or the earliest animals on Earth", study co-author Jochen Brocks, an associate professor with the Research School for Earth Sciences at The Australian National University (ANU), said in a statement.


"These fossils were located in the middle of cliffs of the White Sea that are 200 to 330 feet (60-100 m) high".

The creature was part of the Ediacara Biota that lived on Earth during a time when bacteria reigned, 542-635 million years ago.

Scientists have long debated what the Dickinsonia species actually is - a large amoeba, a lichen, or an animal. "I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone and repeat this process until I found the fossils I was after".

According to Summons, who was not involved in the study, now that the scientists have demonstrated that this particular site and collection of fossils is fertile ground for molecular analysis, much more work will follow to unravel the mysteries of ancient animals like Dickinsonia.

They belong to the Ediacaran biota, a group of soft-bodied organisms that lived on Earth 20 million years prior to the 'Cambrian explosion' of modern animal life. In a related Perspective, Roger Summons and Douglas Erwin write: "Further refining of the phylogenic signals from biomarkers may also help to resolve the early history of animals during the Cryogenian and early Ediacaran". This makes it surprisingly hard to tell what finds in the fossil record are animals and which are plants.

"It is the exact type and composition of that fat that was the giveaway that Dickinsonia was in fact an animal,"said Jochen Brocks of the Australian National University, one of the authors on the study". The find expands the confirmed existence of animals by three million years.

Ultimately, Brocks said, understanding "what these strange-looking Ediacaran creatures really were.is essential if we want to understand the emergence and evolution of our own earliest ancestors".

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