A new study shows that a bristly armored "worm" that scuttled across ocean reefs 518 million years ago is the progenitor to three aquatic animal groups that are very different today.
The fossil of a species that gave rise to brachiopods, bryozoans, and phoronids was found by an international team of researchers.
Scientists reported in a new study that a fossil species is part of an older group of organisms.
The find adds to the puzzle of how animals evolved during the Cambrian explosion, a time when early life diversified rapidly on Earth, introducing and establishing a variety of different body plans.
bryozoans have crowns of tentacles and phoronids have protective tubes made of chitin.
Prior to the discovery of W. bengtsoni, taxonomists had thought that the group's ancestors could have been a worm-like tommotiid.
Researchers had an idea of what this hypothetical descendant might look like, but they didn't know if they would ever find it.
"One of the things that we often mentioned when we were sitting in the pub and fantasizing about what we could hope to potentially find one day was this elusive tommotiid," co-author Jakob Vinther, an associate professor of macro evolution at the University of Bristol in England,
Scientists are puzzled by the poop of an ancient creature.
There is a fossil site in southwest China. It's a rare find because animals like this aren't preserved well enough to be studied in detail.
The shallow tropical waters were where they were scuttling.
In the ancient reef systems, dead animals were washed around until they died and their soft tissues rotted before fossils could be found.
It was lucky for us that the animal was washed down into deep water and buried in mud.
Some of the features in the fossil were a big surprise. The flaps on the animal's body could have been used to fix it to the reef.
The bristles on the sides of the species may have been used to protect it from predatory animals.
The authors of the study don't know what the animal ate, but they know it wasn't a filterfeeder like its descendants.
The researchers think it's the descendant of brachiopods, bryozoans, and phoronids because of its similarity to those groups. Different body plans were adopted by animals as life evolved.
Ancestors may look very different from their living relatives.
Martin Smith, an associate professor of paleontology at Durham University in England, was not involved in the study. Smith said it was a great study.
How these groups fit together and how they evolved from a single common ancestor are what we are seeing. Smith said it was taking them up a rung in the evolutionary tree.
When all the complex body plans appear, we're really starting to see the origin of the Cambrian explosion.
The study was published in September.
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The original article was published by Live Science. The original article can be found here.
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