Meet the new 'Dune' monster, an ancient bladed sea worm

This geological formation stretches across northern Utah and southern Idaho, U.S., and is renowned for hosting an array of Cambrian trilobites and soft-bodied fossils. 

"One of the last times we were out there, 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. Immediately, I showed it to (lead author) Julian Kimmig. He was perplexed. He's said, 'I've never seen anything like that.'"

Determined to uncover its true nature, LaVine transported the fossil specimen to the KU Biodiversity Institute and engaged experts from the University of Missouri. 

The researchers conducted advanced analysis, including scanning electron microscopy and energy-dispersive X-ray spectrometry. The results negated the possibility of mineral growth, confirming the fossil as an unprecedented find.

"We mainly wanted to make sure that this was a biological thing because it's possible it could have just been some weird mineral growth with the way it looked," said LaVine. 

"It's about 7 or 8 centimeters long, maybe a little shorter than the length of a smartphone," she added.

The creature was identified as a previously unknown species of annelid, a diverse phylum encompassing around 21,000 segmented worm species living globally in terrestrial, freshwater, and marine environments (think earthworms and leeches).

Fossil preservation

LaVine fittingly christened the newly discovered species "Shaihuludia shurikeni." Shai-Hulud is a homage to the iconic "Dune" novels by Frank Herbert and "shuriken," the Japanese term for throwing star, similar to the worm's blade-like features. 

This discovery holds immense significance, as Cambrian annelids are rarely found in North American fossil records. 

"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,'" said lead author Julien Kimmig, a palaeontologist with the State Museum of Natural History in Karlsruhe, Germany.

He explained this suggests the animal died and was decomposing for a while before it was fossilized.

The research team's diligent efforts also led to reclassifying another Spence Shale fossil, Burgessochaeta, a genus previously exclusive to a famous fossil deposit in Canada.

The astounding revelation underscores the value of scientific exploration and highlights Earth's role as a historical chronicle. As LaVine eloquently states:

 "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 complete study was published in Historical Biology and can be found here.

Study abstract:

The Spence Shale Member of the Langston Formation in northern Utah and southern Idaho preserves generally non-biomineralized fossil assemblages referred to as the Spence Shale Lagerstätte. The biota of this Lagerstätte is dominated by panarthropods, both biomineralized and soft-bodied examples, but also preserves diverse infaunal organisms, including species of scalidophorans, echinoderms, lobopodians, stalked filter feeders, and various problematic taxa. To date, however, only a single annelid fossil, originally assigned to Canadia sp., has been described from the Spence Shale. This lone specimen and another recently collected specimen were analysed in this study using scanning electron microscopy and energy dispersive X-ray spectrometry. The previous occurrence was reassigned to Burgessochaeta cf. B. setigera. The new fossil, however, has been identified as a novel polychaete taxon, Shaihuludia shurikeni gen. et sp. nov., characterised by the presence of fused, bladed chaetae and a wide body. The occurrence of Burgessochaeta is the first outside the Burgess Shale and its vicinity, whereas Shaihuludia shurikeni gen. et sp. nov. adds to the diversity of annelids in the middle Cambrian and highlights the diversity of the Spence Shale Lagerstätte.