May 24, 2024

Fabulous 500-million-year-old annelid named after Dune’s epic sandworms

A new species of ancient sea worm with an impressively elaborate set of star-shaped chaetae has been discovered after its puzzling fossilized form was found to be animal not mineral. And just as impressive, the 500-million-year-old aquatic annelid has been honored with a name paying tribute to sci-fi author Frank Herbert’s iconic supersized sandworms, the Shai-Hulid, which occupy the planet Arrakis in the Dune novels (and subsequent adaptations).

“I was able to name its genus – so I can put that feather in my cap,” said co-author of the study, Rhiannon LaVine, a palaeontologist at the University of Kansas. “It was the first thing that came to mind, because I’m a big ol’ nerd and at the time I was getting really excited for the Dune movies.”

While the newly named worm is considerably smaller than Herbert’s beasts, its name fits; Shai-Hulid roughly translates to “old man of the desert” or “old father eternity.”

This ancient sea worm, full name Shaihuludia shurikeni, was discovered in the Spence Shale Lagerstätte, an area that covers northeastern Utah and southeastern Idaho and is considered a treasure trove for housing Cambrian trilobites and soft-bodied fossils.

“I split open one of these pieces of rock and instantly knew it was something that wasn’t typical,” LaVine said. “The first thing we see are these radial blades that look like stars or flowers.”

She showed it to the paper’s lead author, Julian Kimmig, who was “perplexed”.

“We were out with Paul Jamison, a local who’s been working the site for years – and if there’s something in there that somebody’s seen, he’s seen it,” LaVinne said. “But he hadn’t seen it.”

Electron microscopy and energy-dispersive X-ray spectrometry conducted by LaVine and scientists at the University of Missouri was able to confirm the fossil was indeed biological, and not mineral, and, even more surprisingly, a never-before-seen worm and a very unexpected discovery in the region.

SEM-EDS map that shows concentrations of Fe, Mn, and Si in the blade-like structures, supporting the hypothesis that the specimen is a fossil and not a collection of mineral growths

“Annelids are very rare in the Cambrian of North America, and so far we only knew of a single specimen from the Spence Shale,” said Kimmig, a paleontologist with the State Museum of Natural History in Karlsruhe, Germany. “The new annelid Shaihuludia shurikeni is especially interesting, as it had some very impressive chaetae, which makes it unique among the Cambrian annelids.

“The way that the fossil is preserved is also of particular interest, because most of the soft tissue is preserved as an iron oxide ‘blob,’ suggesting the animal died and was decomposing for a while before it was fossilized,” he continued. “However, with the analytical methods used in the paper, we show that even with limited preservation you can identify fossils.”

The impressive chaetae, which adorn the length of its 7-8-cm (2.6-3.1-in) body, fittingly became the focus of its species name. “Shuriken” is the Japanese word for throwing star.

There are some 21,000 diverse annelid (or segmented worm) species found on land and in water across the globe.

When the S. shurikeni was alive, marine life was dominated by many alien-like trilobites, brachiopods, mollusks and early forms of arthropods. But a lot has changed in a few hundred million years.

“This discovery gets us to think about deep time,” LaVine said. “We can let our imaginations go a little bit to imagine what happened a million years ago or, in this case, over 500 million years ago. What does the ocean look like then? You’re going to see a lot of the similar players, but they’re a little bit alien because evolution has taken place. It’s very cool to think about our planet as a record of history and all of the different environments that have happened over billions of years, all on the same ground we stand on. We’ve had alien worlds beneath our feet.”

The research was published in the journal Historical Biology.

Source: University of Kansas

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