Scientists have recently discovered an animal fossil dating nearly 20 million years earlier than the Cambrian explosion of life. This first known fossil existed 558 million years ago, while the Cambrian explosion happened 540 million years ago. That’s when modern looking animals such as snails and arthropods emerged.
The newly discovered fossil, named Dickinsonia, was an oval-shaped creature part of an ancient group of organisms called Ediacarans. Ediacarans are some of the earliest complex organisms on Earth but little is known about their evolutionary lineage. The evolution of Ediacarans is still not fully understood by scientists, but this discovery starts connecting these organisms to known animals. Scientists have confirmed that Dickinsonia was an animal, its remains contain a cholesterol that is only found in animals.
“Now we know that animal life started before the Cambrian, in the Ediacaran. That’s very clear now in a way that it wasn’t 15 years ago. But they still look very different from modern animals. The transition between Dickinsonia to even the animals you find in the Cambrian is still quite a large one – we’re still not clear how that happened,” said Emily Mitchell, who works on Ediacarans at the University of Cambridge.
The fossil was found on a cliffside in northwest Russia, by Ilya Bobrovskiy, a PhD student and lead author of the paper published in journal Science. He flew to the middle of the cliffs, which are 60 to 100 meters high on the White Sea, by helicopter and dug blocks of sandstone out. He washed them and repeated the process until he found the fossils.
As a result of this discovery, scientists are beginning to understand more about Ediacaran organisms. Understanding how Ediacaran creatures evolved will allow us to understand the evolution of our own ancestors.
[Source: The Guardian]