Earth's first ecosystems were more complex than thought

Earth's first ecosystems were more complex than previously thought, researchers have found after studying the mode of feeding of a 555-million-year-old organism.
A team of researchers from Canada, UK and US studied fossils of the extinct organism called Tribrachidium, which lived in the oceans.
Using a computer modelling approach called computational fluid dynamics, they were able to show that Tribrachidium fed by collecting particles suspended in water. This is called suspension feeding and it had not previously been documented in organisms from this period of time.
Tribrachidium lived during a period of time called the Ediacaran, which ranged from 635 million to 541 million years ago.

This period was characterised by a variety of large, complex organisms, most of which are difficult to link to any modern species.
It was previously thought that these organisms formed simple ecosystems characterised by only a few feeding modes, but the new study suggests they were capable of more types of feeding than previously appreciated.

"For many years, scientists have assumed that Earth's oldest complex organisms, which lived over half a billion years ago, fed in only one or two different ways. Our study has shown this to be untrue, Tribrachidium and perhaps other species were capable of suspension feeding," said Simon Darroch, Assistant Professor at Vanderbilt University in US.

"This demonstrates that, contrary to our expectations, some of the first ecosystems were actually quite complex," he added.
"The computer simulations we ran allowed us to test competing theories for feeding in Tribrachidium. This approach has great potential for improving our understanding of many extinct organisms," said Imran Rahman, Research Fellow in University of Bristol's School of Earth Sciences in UK.
The study was published in the journal Science Advances.