Sydney: Scientists may have discovered the oldest ever fossils of animal bodies, primitive sponge like creatures that lived in ocean reefs about 635 million years ago.
The shelly fossils, found beneath a glacial deposit in south Australia, represent the earliest evidence of animal body forms in the current record, predating other evidence by at least 70 million years.
"These scientists have found that animals may have appeared on earth 90 million years earlier than previously known," said H. Richard Lane of the National Science Foundation`s Division of Earth Sciences in the US that funded the research.
Previously, the oldest known fossils of hard-bodied animals were from two reef-dwelling organisms that lived around 550 million years ago, reports the journal Nature Geoscience.
Princeton University geoscientists Adam Maloof and Catherine Rose chanced upon the new fossils while working on a project focused on the severe ice age that marked the end of the Cryogenian period 635 million years ago, said a Princeton release.
Their findings provide the first direct evidence that animal life existed before -- and probably survived -- the severe "snowball earth" event known as the Marinoan glaciation that left much of the globe covered in ice at the end of the Cryogenian.
"We were accustomed to finding rocks with embedded mud chips, and at first this is what we thought we were seeing," Maloof said.
"But then we noticed these repeated shapes that we were finding everywhere -- wishbones, rings, perforated slabs and anvils. We realised we had stumbled upon some sort of organism, and we decided to analyse the fossils."