[Animals] Scientists discover what could be the oldest animal on Earth: it is 890 million years old

[MosterOfficial ☆]

 

This discovery casts doubt on the theory, established for decades, that animals appeared on Earth only after the atmosphere and oceans received a major injection of oxygen.

 

But until now, no sponge fossils from that period, known as the Neoproterozoic, have been detected. Elizabeth Turner, a professor at the Canadian Laurentienne University, searched for these fossils in geological layers of reefs dating back 890 million years, reefs "made" by bacteria that were depositing calcium carbonate.

The researcher identified tiny tubular structures containing contemporary reef calcite crystals, which closely resemble the skeleton found in modern sponges. If this discovery, published in the journal Nature, is confirmed, the age of these fossils would exceed by about 350 million years that of the oldest animal remains known to date. “The most primitive animals that appeared in a process of evolution were probably sponges. Which is not surprising since sponges are the simplest animals in the tree of animal life, "he explained to AFP. If it is confirmed that the fossils that the scientist found, barely one centimeter in length, were sponges, those first traces of life lasted about 90 million years, until the Earth accumulated a sufficient level of oxygen for the appearance of animal life more complex, in the Neoproterozoic. "If my interpretation is fair, the early animals ... tolerated relatively lower oxygen levels than current conditions," he explained.

 

Animals