Uruguayan scientists have discovered the oldest animal life proof in the world. The discovery has taken place thanks to fossils 585 million years ago. These fossils are 30 million years older than those previously discovered. They were found in the Cerro Largo department.
The team of researchers discovered in Uruguay the evidence of bilateral animals (animals that have a front face, a back face, an upper and a lower region) from more than 585 million years ago. It is the trace of a series of tiny earthworms that were moving along the seabed. They are furrows left by worms when move across the ocean in the area that today is Cerro Largo, Treinta y Tres and Rocha.
Ernesto Pecoits, geologist from the Faculty of Sciences of the University of the Republic and researcher at the University of Alberta, Canada, and main author of the study, comments that “The most important thing is that the most ancient ancestors were discovered, the first animals that inhabited the planet and were able to move, to move”. The study does it together with Natalie Aubet.
The earliest previous discovery was found in russia, in the White Sea area, Pecoits claims, and they have 555 million years. “With this discovery, the origin of animals with mobility is being stretched backwards”Says Pecoits.
The beginning of animal life had its origin in the aquatic environment. The species were evolving to the point of become resistant to the living conditions of the terrestrial environment. "What we are most used to seeing in documentaries is that fish evolve into amphibians and then reptiles and some vertebrates came, ”says Pecoits. But that happened in the last 500 million years. We are talking about what would be the ancestor of all those animals”.
Is a primitive way of life. It is a kind of worm of barely one millimeter wide and five long. "It is the ancestor of all animals that exist on Earth, including ourselves”Says Pecoits. They are thought of as ancestors of animals by its bilateral symmetry. “We have an upper part, a lower part, a back part and a front part. This animal also has them, that is why it is our ancestor, it is the first to present them”Says the researcher.
The fossils found in Australia and Oman predate those found in Uruguay, but their way of life was much more basic. However, the recently found ones have current animal characteristics like musculature and the ability to move. "From the appearance of these sponges to the animals that produced these traces there is a very big evolutionary leap", it states.
The samples were found in an area known as ‘Tacuarí foundation ’, near the river of the same name south of the city of Melo, in the department of Cerro Largo. Geologists have called the area 'foundations' due to rock characteristics.
Pecoits and Aubet had been working there for a decade thinking that the rocks weren't that old. They were believed to date from 200 million years, since in this period there were already bilateral animals. Therefore, when they found the grooves they were not too surprised. However, they had to identify another rock to know his age. A kind of granite cut through the grooves. When analyzing it, they found that they were igneous rocks formed from solidified lava. "That lava went through the tracks like it was a dam”Says Pecoits. The stone below would be oldest.
Later the samples were analyzed in Canada, where the granite was separated to be able to date it and know when it was formed. "The age we obtained was 585 million years. There we realized that all the fossils and the rock that had been cut out were older”Aubet comments.
After knowing this information, they began to do more tests to corroborate it by carrying out various analyzes and working with specialized laboratories in Australia. They all had the same result: granite was 585 million years old.
The next piece of information to find out was the age of fossils. To do this, they analyzed the minerals obtained from the fossils and verified that its maximum age was 600 million years. This is a great discovery, since it was thus learned that “organisms generated those traces, those grooves, between 600 and 585 million years ago”Explains Aubet. The discovery took place in 2007 and scientific studies have been carried out for three years to demonstrate the findings.
The samples are on display at the University of Alberta Museum of Paleontology. They will be made duplicates to send to Uruguay. In addition, the necessary steps will be taken so that the Tacuarí formation is declared protected area.
"It is the oldest evidence"
Despite the fact that the Earth is about 4.6 billion years old, it was estimated that between 3,500 and 555 only bacteria had existed, single-celled organisms, and primitive life forms such as sponges.
So far, the most complex sample of animal life ever found it was 555 million years old. After this, he commented on the so-called Cambrian period, considered as an explosion of animal life. However, thanks to the Pecoits find, this apparition is known to recede to a previous period.
In the issue of Science where the study is published, James Gehling, principal investigator at the South Australian Museum of Paleontology, has analyzed the scientific impact of the fossils found. Gehling assures that “the fossils represent a really important discovery. These structures were clearly made by very small mobile animals that inhabited the ocean floor.”.
Now begins a period in which Pecoits and his colleagues have to demonstrate the validity of the techniques used to date fossils. "The possibility that the age is not exactly what they defined is remote, but it must continue to be analyzed. Anyway, it's clearly the oldest mobile animal evidence out there.”, He concludes.
Graduated in Journalism and Audiovisual Communication, since I was little I have been attracted to the world of information and audiovisual production. Passion for informing and being informed of what is happening in every corner of the planet. Likewise, I am pleased to be part of the creation of an audiovisual product that will later entertain or inform people. My interests include cinema, photography, the environment and, above all, history. I consider it essential to know the origin of things to know where we come from and where we are going. Special interest in curiosities, mysteries and anecdotal events in our history.