Scientists have used fat molecules to solve a longstanding mystery and identify an ancient creature as one of the earliest animals on the planet.
For more than 75 years, researchers have struggled to classify the Dickinsonia, a peculiar, vaguely jellyfish-like creature that lived about 558 million years ago. The flat, squishy, oval-shaped organism had multiple rib-like segments and could grow to over four feet long, according to National Geographic.
Advertisement
Dickinsonia belonged to a group of now-extinct life forms called the Ediacaran biota. These creatures, believed to have emerged in warm, shallow seas as early as 570 million years ago, are thought to be the first complex multicellular organisms on Earth.
But scientists were unable to determine exactly what Dickinsonia were, classifying them either as fungi, protists or animals.
Now, an international team of researchers has used modern chemistry to unearth striking evidence that Dickinsonia were indeed early animals. Their study, published this week in the journal Science, hinges on fat.
Advertisement
Researchers from the Australian National University, with help from other institutions, found Dickinsonia fossils that contained significant levels of cholesterol ― a hallmark of animal life.
Dickinsonia were floating around before the Cambrian explosion 540 million years ago, when an abundance of new and diverse life forms like mollusks, worms, and sponges appeared in the fossil record within a relatively short time.
That’s significant because Dickinsonia’s fossil fat molecules prove that “animals were large and abundant” on Earth “millions of years earlier than previously thought,” according to ANU senior researcher 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 palaeontology,” Brocks said in a press release.
Advertisement
The problem that was holding researchers back for so long was that Dickinsonia and other Ediacarans have boneless bodies that weren’t easily preserved. Scientists have typically studied the creatures by physically analyzing their ancient imprints.
But Ilya Bobrovskiy, a Ph.D. student at Australian National University, had a hunch that he could extract and analyze biomarkers from a thin layer of organic material left in particularly well-preserved Dickinsonia fossils.
Most of the rocks containing Dickinsonia fossils near Bobrovskiy’s university in Australia had endured a tremendous amount of natural heat, pressure and weathering over the centuries. So he traveled to a remote area in northwest Russia to hunt for the fossils he needed.
“I took a helicopter to reach this very remote part of the world - home to bears and mosquitoes - where I could find Dickinsonia fossils with organic matter still intact,” Bobrovskiy said in the release.
He eventually found good candidates for his research in some 330-foot cliffs near the White Sea.
“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,” he said.
Advertisement
Bobrovskiy then developed a special technique to test the Dickinsonia remnants for cholesterol.
Brocks said that when Bobrovskiy showed him the results of the tests, he “just couldn’t believe it.”
“But I also immediately saw the significance,” Brocks said.
The study depends on the assumption that only animals can produce cholesterols, which some scientists suggest could be disproven as more research is conducted on the Earth’s earliest inhabitants.
“There’s a lot of uncertainty,” Bobrovskiy said of studying such ancient life. “But applying biomarkers removes a large part of this uncertainty.”
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.