Scientists from the University of St Andrews in Scotland have discovered fossils of Otavia antiqua, the first animals that lived on Earth. Otavia antiqua are sponge-like fossils aged between 760 and 550 million years ago.

The discovery was made at Namibia's Etosha National Park and other sites around the country.

Otavia antiqua are tiny vase-shaped sponge and look like specks of dust. The Otavia antiqua had lots of holes in their bodies which allowed them to feed on bacteria and algae.

According to scientists, otavia antiqua are multi-cellular organisms that lived before the ice age and these creatures were tough enough to survive the worst cold weather conditions, according to research published in the South African Journal of Science.

"If one looks at the family tree and projects this backward to where you have what's called the stem group, the ancestor of all animals, then yes, this would be our great-great-great-great-great-great-great grandmother," Tony Prave, a geologist at the University of St Andrews in Scotland, told to AFP.

"The aspect of this that's rather satisfying, at least intellectually, is that it is in broad agreement with what geneticists would tell us based on looking at molecular clocks when we should see the first advent of large multi-cellular life forms," he said.