“It’s going to be the first sponge fossil from the Precambrian,” said Paco Cardenas, an expert on sponges in Uppsala. “And not just from the Precambrian, but from much before that – that’s the most exciting thing about it.” University in Sweden. He added that the research appears to confirm molecular clock estimates.
“The most beautiful thing about it is dating,” Cardenas said. “The discovery of fossil sponges dating back nearly 900 million years will greatly improve our understanding of the evolution of the first animals.”
This dating also means, if it is confirmed that they are indeed fossil sponges, then animal life evolved prior to two important events in Earth’s history that were always thought to precede the emergence of animal life.
The first is the last of two periods in the planet’s history when the amount of oxygen in the atmosphere increased dramatically, between about 830 and 540 million years ago. Scientists assumed that only after this increase would the oxygen level be high enough to allow animal life to appear. However, recent research has shown that some sponges can survive on very little oxygen.
The second major event was a very cold period during which the Earth was probably covered with ice or at least partially frozen, sometime between 720 and 635 million years ago.
NS Professor Elizabeth Turner’s study was published in nature. This article is based on a telex from the Associated Press and a telex from Reuters.