Oldest ever animal fossils discovered

摘要

THE origin of animals may have happened 350 million years earlier than thought. Fossils that seem to be sponges, one of the first animals to evolve, have been found in rocks from 890 million years ago. "It seems at first glance that this is a very radical paper," says Elizabeth Turner at Laurentian University in Sudbury, Canada, who made the discovery. However, she says the fossils she found fit with other evidence. Most animals are multicellular organisms whose bodies are made up of distinct tissues and that have to eat food to survive. For years, the earliest-known animal fossils were from the Cambrian Period, which began 541 million years ago. However, in recent years, some fossils from the earlier Ediacaran Period (635 to 541 million years ago) have been identified as animals. There are also 660-million-year-old chemical traces that may be from sponges.