Through a careful analysis of fossilized seabed layers dating back about 20 million years, scientists have reconstructed the lair of a giant underwater worm that most likely remained hidden in sediment before jumping to ambush prairie.
The newly identified creature is probably an ancestor of Eunice aphrodisiac or the bobbit worm that exists today, say researchers – these scary-looking modern creatures can grow up to 3 meters in length, grabbing and catching their food with strong jaws and sharp mouthparts.
While the history of worms like these is already believed to stretch back hundreds of millions of years – perhaps to the early Paleozoic – their soft parts of the body mean that there is a largely incomplete fossil record for them, which makes this new discovery to be significant.
The team behind the new study recovered and processed 319 specimens to reconstruct a fossil footprint (the footprint of an animal, rather than the animal itself), an L-shaped burrow over 2-3 centimeters in diameter (0.8-1 , 2 inches) up to 2 meters (about 6 and a half feet) in length.
It has been called the fossil record, which is also known as the ichnospecies Pennichnus beautiful!; based on an analysis of the size and shape of the burrow, as well as the signs of disturbance left in the rock, it seems to have hosted an ancient worm that also jumped from the bottom of the sea to catch prey.
“These morphological features of Pennichnus they are consistent with the activities of an ambush predator, and therefore we assume that giant polychaetes, such as bobbit worms, are the most likely producers of traces, “the researchers write in their paper.
One of these morphological features is the high concentration of iron at the top of the den. This suggests that ancient worms used mucus to rebuild their burrows after the attack, because the bacteria that fed on this mucus would have left traces of iron.
Other potential inhabitants of P. formosa, including shrimp and molluscs, were excluded: shrimp tend to make burrows lighter and more complex, while the shape and structure of burrows do not match the patterns left by molluscs.
The findings cover a gap in our knowledge of how this type of creature evolved and developed over time – and how dramatic life (and death) has been at the bottom of the oceans for millions of years.
“To summarize, we hypothesize that about 20 million years ago, on the southeastern border of the Eurasian continent, the worms of the ancient bobbit colonized the seabed, waiting in ambush for a passing mass,” the researchers write.
“When the prey approached a worm, it exploded from the burrow, grabbing and pulling the prey into the sediment. Under the seabed, the desperate prey sank to escape, leading to the disturbance of the sediment around the opening of the burrow.”
The research was published in Scientific reports.