TWO AMERICAN scientists on a research mission have stumbled across a fossil that they believe to be the oldest ever specimen of animal life on Earth: at 650 million years old.

The scientists – professor Adam Maloof and graduate student Catherine Rose, from Princeton – published their findings in the magazine Nature Geoscience, and said that they had come across the fossils in Australia when researching a massive ice age, known as ‘the snowball effect’.

The era, about 635 years ago, left much of the planet covered in such thick ice that most believed no animal life could have survived the era – but inspecting a glacial deposit on the south of the country, they found their fossils.

The fossils are those of a sponge-like creature that lived on the ocean reef, with a series of internal canals likely used to separate food from water.

Said Maloof:

No one was expecting that we would find animals that lived before the ice age, and since animals probably did not evolve twice, we are suddenly confronted with the question of how some relative of these reef-dwelling animals survived the ‘snowball Earth’.

We were accustomed to finding rocks with embedded mud chips, and at first this is what we thought we were seeing. 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.

The earliest fossils of similar creatures before now came from about 520 million years ago, while more hard-bodied animals are known to have lived at least 550 million years ago.