"Most rocks containing these fossils, such as those from the Ediacara Hills in Australia, have endured a lot of heat, a lot of pressure, and then they were weathered after that - these are the rocks that palaeontologists studied for many decades, which explained why they were stuck on the question of Dickinsonia's true identity." In a new study, published this week in Science, researchers used modern techniques to take a fresh look at the ancient creatures. Their results join mounting evidence that suggests Dickinsonia is among the earliest animal life yet found—predating the Cambrian explosion of life, which took place 541 million years ago and marked the rise of most major animal groups still around today. Credit: The Australian National University (ANU) Scientists from The Australian National University (ANU) and overseas have discovered molecules of fat in an ancient fossil to reveal the earliest confirmed animal in the geological record that lived on Earth 558 million years ago. Because the Ediacaran bodies are largely imprints, no one had attempted to test for biomarkers of these ancient weirdos. Palaeontologists normally study the structure of fossils, but Mr Bobrovskiy extracted and analysed molecules from inside the Dickinsonia fossil found in ancient rocks in Russia to make the breakthrough discovery. ANU Ph.D. scholar Ilya Bobrovskiy discovered a Dickinsonia fossil so well preserved in a remote area near the White Sea in the northwest of Russia that the tissue still contained molecules of cholesterol, a type of fat that is the hallmark of animal life. Dickinsonia belongs to a group of life forms known as the Ediacaran biota. Scientists from The Australian National University (ANU) have discovered molecules of fat in an ancient fossil to reveal the earliest confirmed animal in the geological record that lived on Earth 558 million years ago. As such, they straddle an ancient age when the Earth was dominated by bacteria and a later age of dominance by animals.
– A researcher calls it "a decades-old mystery that has been the Holy Grail of paleontology": What, exactly, Dickinsonia was. It's one of a group of lifeforms called the Ediacaran biota, which the BBC describes as the "first complex multi-cellular organisms to appear on Earth." But for decades they've defied definitive classification, with scientists suggesting they could be everything from lichen to giant single-celled amoeba to "evolutionary dead-ends." Now, an answer: Dickinsonia is an animal that dates back 558 million years, making it the earliest confirmed one in the geological record. That conclusion comes thanks to fat, reports Phys.org. Ilya Bobrovskiy of Australian National University discovered a Dickinsonia fossil in 300-foot-high cliffs along the White Sea in northwest Russia, in a place so remote she reached it via helicopter. The fossil was superbly preserved, so much so that its tissue had cholesterol molecules present in it. "The fossil fat molecules that we've found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought," says ANU professor Jochen Brocks, co-author of the paper on the discovery, which was published in Science. The Cambrian explosion that gave rise to modern animal groups didn't happen for another 20 million years or so. As for the oval Dickinsonia's appearance, the BBC describes it as possibly bearing "a superficial resemblance to a segmented jellyfish." National Geographic delves into the difficulty of studying Ediacarans, who had no shells or bones to leave behind and whose "squishy bodies have long since decayed." Read more on how the team overcame that here.