Group of prehistoric sea creatures are millions of years younger than previously thought

By Alice Clifford via SWNS

A group of prehistoric sea creatures are millions of years younger than previously thought after a new study of fossils revealed they're actually SEAWEED.

The fossils were believed to be the oldest Bryozoans, tentacle-bearing animals that lived in skyscraper-like underwater colonies.

However, ancient fossil material discovered in China revealed previously unseen “soft parts” in the earliest Bryozoan fossils.

This fragile tissue exposed that the fossil was in fact a member of the green algal group Dasycladales.

Study co-author Professor Zhang Xiguang, of Yunnan University, said: “Where previous fossils only preserved the skeletal framework of these early organisms, our new material revealed what was living inside these chambers.

“Instead of the tentacles we would expect to see in Bryozoans, we discovered simple leaf-like flanges – and realized we were not looking at fossil animals, but seaweeds.

“This means that the oldest convincing Bryozoan fossils do not evolve until the next geological period, the Ordovician.”

The Ordovician period was 480 million years ago, 40 million years after the Bryozoan were thought to have appeared.

This discovery makes them the only group of fossil animals not to appear in the Cambrian “explosion” – a rapid burst of evolution that happened 40 million years earlier.

Study co-author Dr. Martin Smith, of the Department of Earth Sciences at Durham University, said: “We tend to think of the ‘Cambrian explosion’ as a unique period in evolutionary history, in which all the blueprints of animal life were mapped out.

“Most subsequent evolution boils down to smaller-scale tinkering on these original body plans.

“But if Bryozoans truly evolved after the Cambrian period, it shows that evolution kept its creative touch after this critical period of innovation – maybe the trajectory of life was not set in stone half a billion years ago.”

Whilst the origin of animal groups may not have been so sudden, we now know that this seaweed played a larger part in the early oceans than previously thought.

The findings were published in the journal Nature.