Through a careful analysis of fossilized seabed layers dating back some 20 million years, scientists have reconstructed the lair of a giant underwater worm that would probably have been hidden in sediment before jumping to ambush its prey. .
The newly identified creature is likely to be an ancestor of the Eunice aphrodisiac or the bobbit worm that exists today, researchers say, that these terrifying-looking modern creatures can grow up to 3 feet long, grabbing and trapping food with powerful jaws and sharp mouthparts.
Although the history of worms like these is already believed to date back hundreds of millions of years, perhaps to the early Paleozoic, their soft body parts mean that there is a largely incomplete fossil record, which makes this new finding significant.
The team behind the new study recovered and processed 319 specimens to reconstruct a fossil trace (the trace of an animal, rather than the animal itself), an L-shaped den about 2-3 centimeters (0.8). -1.2 inches) in diameter and more than 2 meters (approximately 6 feet and a half) long.
The fossil trace, also known as ichnospecies, has been named Pennichnus bonic!; based on an analysis of the size and shape of the den, as well as the signs of disturbance left in the rock log, it appears to have housed an ancient worm that also jumped from the seabed to capture prey.
“These morphological features of Pennichnus they are consistent with the activities of an ambush predator, and we therefore hypothesize that giant polychaetes, such as bobbit worms, are the most likely trace makers, ”the researchers write in their article.
One of these morphological features is the high concentration of iron towards the top of the den. This suggests that ancient worms used mucus to rebuild their lairs after attacking, as bacteria feeding on this mucus would have left traces of iron.
Other potential inhabitants of P. formosa, including prawns and molluscs, were discarded: prawns tend to make more open and complex nests, while the shape and structure of the nests do not match the patterns left by mollusks.
The findings fill a gap in our knowledge of how this type of creature evolved and developed over time, and how dramatic life (and death) has been on the ocean floor for millions of years.
“In short, we hypothesize that about 20 million years ago, on the southeastern border of the Eurasian continent, ancient bobbin worms colonized the seabed waiting for an ambush to eat in passing,” the researchers write.
“When the prey approached a worm, it exploded from its lair, grabbing and dragging the prey to the sediment. Beneath the seabed, the desperate prey sank to escape, causing a new sediment disturbance around the opening of the den “.
The research has been published in Scientific reports.