Scientists have found evidence of the existence of complex forms of life on Earth half a billion years ago.
An international team of paleontologists, headed by scientists from the University of Manchester, found fossils older than half a billion years. These traces, probably the first or one of the first complex living organisms on our planet will help to shed light on the evolutionary history of life, scientists believe.
The results of a study published in Nature Ecology & Evolution.
Unfortunately, discovery is not the physical remains of living organisms. This is the traces of their activity – holes, carried out in sedimentary rocks. The discovery was made in the Western part of Brazil. The diameter of the holes ranges from 50 to 600 micrometers, and this means that the creatures that they did, was a little thicker than a human hair.
Fossils relate to the geological and evolutionary period at the junction of ediacaran (635-542 million years ago) and Cambrian (541-485 million years ago). This transition period is extremely important in the evolutionary history of life.
“It is particularly exciting this discovery makes the age of rocks: fossils, probably, are witnesses of the oldest complex life forms,” says study author Russell Garwood. – Evolutionary events during the transition from the Cambrian to ediacaran are unparalleled in Earth’s history. The current fossil record suggests that many of the life forms known today, appeared in a very short period of time.”
In his opinion, the burrows found in rocks, were created by the organisms like nematodes (roundworms). When moving between layers of rocks they left behind tiny tunnels. These tunnels have symmetrical grooves, indicating that the ancient worms have not used peristalsis (the contraction and elongation of the body) for movement. Most likely, they moved in waves, like rocking their bodies from side to side to “swim” through rock like it was a liquid, said co-author Luke Perry of the University of Bristol.
By the way, to detect such microscopic traces, the team used x-ray microtomography. X-rays have helped to create a 3D virtual model without destroying the object under study.