The oldest known animal on Earth, dating back 558 million years, is probably a strange sea creature with fossils resembling a cross between a leaf and fingerprints.
As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate discovery in a remote area of Russia: a Dickinsonia fossils with fat molecules still attached. These strange, oval-shaped creatures with a soft body, with rib structures running down their sides, grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in a summary of a new paper published in the journal Science.
Ged Dickinsonia fossils were first discovered in South Australia in 1946, researchers did not find the organic matter needed to classify this creature. “Scientists have been fighting for over 75 years for what it is Dickinsonia and there were other strange fossils of the Edicaran biota: large single-celled amoeba, lichen, failed evolution tests, or the earliest animals on Earth, ”said lead author Jochen Brocks, associate professor at ANU, in statement.
When cholesterol molecules are found – found in almost all animals, but not in other organisms such as bacteria and amoebas – scientists can say Dickinsonia of animals. The creatures swam the oceans at the time of Ediacaran, 635 million to 542 million years ago. More complex organisms such as molluscs, worms and sponges did not appear until 20 million years later.
The fossil with fat molecules was found on cliffs near the White Sea in an area of northwestern Russia so remote that researchers had to take a helicopter to get there. Collecting the samples was also very dangerous.
“I had to hang over a cliff edge on ropes and dig large blocks of sandstone, throw them down, wash the sandstone, and repeat this process to can I find the fossils I was looking for, ”said ANU lead author Ilya Bobrovskiy. . Given that this discovery could alter our understanding of the earliest life forms on Earth, it seems worth the risk.
[h/t New Scientist]