Fossils found in Australia could mean that animals appeared at least 70 million years before the earliest known creatures.

Researchers from Princeton University in the US have been investigating the ice age known as the Marinoan glaciation or ‘snowball Earth’, which happened around 635 million years ago and left much of our planet covered in ice. While investigating rock layers, the scientists found some containing what they thought were tiny, ancient animals.

These fossils could not be removed with normal techniques – and X-rays would not work with the material. So, experts shaved off incredibly thin slices of the rocks, and took pictures of it each time. By doing this nearly 500 times, they could use software to piece the images together and build up 3D images of the tiny creatures.

The researchers say that the creatures look most like tiny sponges and are about 650 million years old. They claim that the fossils are the first direct evidence that life existed before the Marinoan glaciation.