A strange creature called Dickinsonia is thought to have been the very first animal on Earth.
If you have ever wondered what Earth was like 600 million years ago, scientists will probably tell you that despite Earth’s continents being lifeless at the time, our oceans were teeming with a variety of lifeforms.
Some 570 million years ago, Earth’s oceans were inhabited by flat, oval creatures, with bodies formed by segments.
They lacked skeletons, they were soft, they moved slowly and it is unknown if they had eyes. Some had a few centimeters, while others were more than one meter in size.
Meet the Dickinsonia Fossil
Since the discovery of the first Dickinsonia fossils 75 years ago, paleontologists had considered numerous hypotheses to try and explain what these creatures were: some speculated that they were lichens, single-celled amoeba, others said that they may have been a variety of sea worms or jellyfish, and some experts had even proposed that they were an assembly of unicellular organisms.
The prevailing theory back then was that the enigmatic creatures were an early form of jellyfish.
Now, researchers from the National University of Australia (ANU) have finally solved the riddle of the Dickinsonia mystery.
According to a recent paper published in Science, the mysterious creatures who lived on Earth during the Ediacaran period represent the earliest known complex life form on Earth.
As mentioned in Science, after studying the fossils thoroughly, researchers discovered tiny molecules of cholesterol. This has led experts to suggest this organism needs to be declared a true animal and not a plant or fungus.
“It is the holy grail of paleontology,” says Jochen Brock, a researcher at the UNA and co-author of the research.
“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.”
“It sheds light on our own origins, hence it is very important to find out what these creatures were ultimately.”
Around 540 million years ago, with the beginning of the Cambrian period, there was a massive explosion of life and diverse animal groups appeared.
The Edicarian Period occurred around 20 million years prior to the emergence of modern animal life — a period known as the Cambrian explosion.
“The question has been, is that real? Is that an event that happened in Earth history? Or have we just not found the older fossils?” David Gold, geobiologist and assistant professor at the University of California, told AFP.
“This paper is another really good line of evidence to support the idea that it is, in fact, an animal, and that animals are much older than the Cambrian.
The Dickinsonia fossils currently studied originated from cliffs near the White Sea in the northwest of Russia.