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(Danielle Dufault/Royal Ontario Museum)

This Bizarre Fossil Worm From 508 Million Years Ago Has Scientists Excited

Even though it looks like a pipecleaner.

23 JAN 2018




Now researchers have found a new species, a bristle-covered worm with long feelers on its head, and it's helping us understand how annelid heads evolved - a group of animals that today includes earthworms and leeches.


Researchers found it in the Kootenay National Park outcrop of the Burgess Shale fossil site in British Columbia, Canada. The place is famed for its exceptional fossils of soft-bodied creatures, documenting a period known as the Cambrian explosion - when the first representatives of most modern phyla appeared on Earth.

The location it was discovered in is called Marble Canyon, a new section of the site found in 2012. So far, it has turned up over 500 K. barbarensis fossils, making it the most abundant annelid species of the time - and providing plenty of material to study.

Many of the fossils were wonderfully and extraordinarily well preserved in the soft mud that hardened over the millennia. It was this exceptional preservation that led to the fossil's importance to the study of annelid evolution.


"Annelids are a hugely diverse group of animals in both their anatomies and lifestyles," said lead author Karma Nanglu, a University of Toronto PhD candidate, and a researcher at the Royal Ontario Museum.


Annelids, or segmented worms, include over 17,000 species living today - from, as mentioned, the common earthworms in your garden to tubeworms dwelling next to hydrothermal vents in the dark depths of the ocean.

Because they're soft-bodied, the annelid fossil record is poor, which has historically made them very tricky to study. The Burgess Shale and similar deposits have given us some excellent fossils, but those are rare - and even then, they are difficult to understand.


bristle worm fossil(Jean-Bernard Caron/Royal Ontario Museum)





Some of the fossils were so well preserved that they included delicate internal tissues, such as what the researchers think might be the worm's nervous tissue. These details can reveal a lot about its life - and also help connect it to modern species.

"508 million years ago, the Marble Canyon would have been teeming with annelids," Nanglu said.


The team's research is due to be published in the journal Current Biology.


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