A geologist brought home some ancient rock 20 years ago. She may have stumbled on the world’s oldest animal fossil

Two decades ago, geologist Elizabeth Turner set out to explore the ancient reefs locked away in the Mackenzie Mountains in north-west Canada.

Her heart was set on understanding how photosynthetic microbes had built huge reefs millions of years ago.

Instead, the then-PhD student walked away with a pile of rocks, a handful of which had some pretty unusual features.

But it turns out that Dr Turner may have stumbled across the earliest known animal fossils, according to a paper published today in Nature.

The tiny structures embedded in the 890-million-year-old rocks look remarkably similar to the skeletons of sea sponges, suggesting that these simple creatures were thriving in the oceans earlier than previously thought.

Dr Turner said the structures were too complex to have been created by algae or bacteria.

“The process of elimination says that it can’t be these other things,” said Dr Turner, who is now based at Laurentian University in Ontario.

“The fact that other workers have found this structure in [younger] fossil sponges kind of put the nail in the coffin.”

But some scientists are sceptical about whether the fossils are sponges or may have even been created by a biological process.

Read full article here