China News Service, July 30. According to the "Central News Agency" report, researchers found deep-sea sponge fossils in the mountains of northwestern Canada, nearly 900 million years ago.
If the inference is correct, these fossils will push the origin of the earth’s animals forward by about 300 million years.
In the rugged mountains of northwestern Canada, researchers have found sponge fossils living on primitive reefs formed by bacteria. These sponge fossils dating back about 890 million years ago may give a glimpse of the origin of animals on the earth.
On the 28th local time, a Canadian researcher said that these fossils, dating back to the Neoproterozoic, seem to have microstructures of their bodies.
It is different from deep-sea sponges that are similar to the Mediterranean bath sponges or bathing hornbone sponges that exist today.
If interpreted correctly, these may be the oldest animal fossils, about 300 million years earlier than previously discovered fossils.
Turner, a geologist at Laurentian University in Canada, who conducted this research, said: “The earliest evolutionary organisms are likely to be sponge-like. This is not surprising, because in terms of current and fossil records, sponges are The most basic animal type." The research report was published in the journal Nature.
According to the report, the earth was formed more than 4.5 billion years ago, and the earliest life forms appeared hundreds of millions of years later, as single-celled marine organisms similar to bacteria; the evolution of complex life occurred relatively late in the history of the earth.
Various circles have been arguing about the time and form of the first appearance of primary animal life.
With mysterious ribs, like pancakes, the fossil organism named Dickinsonia (Dickinsonia) appeared about 575 million years ago and is considered a candidate for the oldest known animal.
Turner believes that the evolution of animals is earlier than the existing fossil record suggests.
When people think of animals, the first thing that comes to mind may not be sponges.
But sponges, aquatic invertebrates that live on the seabed and have soft, porous bodies and endoskeletons, may be one of the most successful animal groups.
If these fossils are indeed some kind of sponges, the time of their appearance will show that the evolution of the oldest animal on the earth is earlier than the two indicator events generally considered to be the appearance of animal life.
One of the events was the moment when the atmospheric oxygen content in the earth’s history surged, about 830 million to 540 million years ago; the other was when the earth was frozen or at least partially frozen and the temperature dropped sharply, which occurred about 720 million years ago. By 635 million years ago.
These fossils are about 350 million years older than the oldest known sponge fossils. Turner pointed out that, according to genetic studies, sponges first appeared about the same time as these fossils.