The ancient Serkirkia worm, with its head covered in rows of curved spines, could easily be confused with the razor-toothed sandworm of the deserts of Arrakis in Dune: Part 2.
These strange insects, which lived in long conical tubes, were some of the most common predators on the ocean floor during the Cambrian Explosion more than 500 million years ago.
“If you were a small invertebrate, that would be your worst nightmare,” says Karma Nangle, a paleontologist at Harvard University. “I feel like I'm being swallowed up by a conveyor belt of fangs and teeth.”
Thankfully for would-be spice harvesters, these voracious insects disappeared hundreds of millions of years ago. But a recently analyzed fossil trove in Morocco reveals that this formidable predator, just 1 to 2 inches long, lasted much longer than previously thought.
In a paper published today in Biology Letters, Dr. Nangle's team describes a new species of Cerkillchia worm that survived 25 million years after this group of tube-dwellers was thought to be extinct.
The newly described tubular worm was discovered when Dr. Nangle and his colleagues scoured fossils held in the collections of Harvard University's Museum of Comparative Zoology. The fossil comes from Morocco's Fezuata Formation, which dates back to the Early Ordovician period, which began about 488 million years ago and lasted about 45 million years. This was a dynamic era in which Cambrian remnants rubbed shoulders with evolutionary newcomers like sea scorpions and horseshoe crabs.
The Fezuata Formation provides a detailed snapshot of its ecological evolution. The site is well known for the remains of marine life such as trilobites, often preserved in rusty shades of red and orange. Some preserved creatures retain delicate soft tissue features that rarely fossilize. Most of the research on Fezuata fossils has focused on these remarkable discoveries, and the vast amount of what Dr. Nangle calls “fossil bycatch” – small remains and fragments that are also contained in Fezuata rocks. Ignoring it.
As the research team combed through the museum specimens, they noticed several fiery-colored fossils of tapered tubes that looked like long ice cream cones. The annular texture of these tubes, which were only 1 inch long, was nearly identical to Cerquilchia fossils from much older Cambrian deposits like the Burgess Shale.
“I don't think this man is going to exist anymore,” Dr. Nangle said. “25 million years out of place.”
Detailed analysis confirmed that the tube belonged to a new species of Serkillchia worm. They gave the new animal the species name Tsering, which means “long life” in Tibetan. This new species not only expands the temporal record of Cerkiluchia worms, but also confirms that they lived in an environment close to the Antarctic region of Morocco during the Ordovician period.
The discovery suggests that despite an explosion in diversity during the Ordovician, some The discovery highlights the ability of Cambrian creatures to survive.
“This new study adds to the evidence that many members of the Cambrian community continued to thrive into the subsequent Ordovician and were not replaced as quickly as previous evolutionary models had suggested. '' he said.
Dr. Caron said the morphology of the new bug “doesn't appear to be significantly different than its Cambrian counterpart.” This suggests that the cercyrrhiza have undergone little evolutionary change during the 40 million years they have spent preying on other seafloor creatures.
But that tube-based body morphology eventually departed from the evolutionary style among closely related nematodes known as priapulids, or penis-shaped nematodes. Currently, there is only one type of priapulid present in the tube, and rather than secreting substances from its own body like the Cercyrrhea worms, it constructs the tubes from chunks of plant debris.
Dr Nangle argues that forming such tubes was a powerful defense during the Cambrian period, when there were fewer large predators roaming the open ocean. However, as free-swimming predators proliferated during the Ordovician, the rigid tubes may have ultimately made these insects easier targets. As a result, these nematodes may have abandoned their tubes and adopted more active escape methods, such as burrowing.
The ecological costs of producing these tubes have probably caught up with the Serkillia bug in the long run, but new discoveries suggest this bug managed to outlast many of the strange wonders of the Cambrian period. I proved that I did it. For Dr. Nangle, their presence suggests that sometimes reality is stranger than fiction, even if they are big-screen lookalikes.
“It's like a dune sandworm building a giant house around itself,” Dr. Nangle says. “No matter how wild what you see on screen, I guarantee you there is something wilder in nature, even if it has been extinct for a long time.”