Fossil-hunters think they have found the lair of a giant, predatory, prehistoric worm

Scientists think they have discovered the undersea lair of a giant predatory worm that lived on the ocean floor some 20 million years ago and would pounce on unsuspecting marine creatures.

Paleontologists from National Taiwan University believe the 6.5-foot-long burrow was once home to a worm-like predator that would surface from the seabed to ambush sea creatures and drag them, alive, into its lair.

Experts working in northeastern Taiwan reconstructed large, L-shaped burrows dating back to up to 23 million years ago from layers of seafloor using trace fossils — geological features, like track marks, burrows and plant root cavities found preserved in rocks, which experts use to draw conclusions on the behavior of ancient creatures.

Using 319 specimens, experts reconstructed a trace fossil of a dugout — dubbed Pennichnus formosae — which was 6.5-feet long and around an inch in diameter, and say morphological evidence indicates that the tunnels were home to giant marine worms, like the modern-day bobbit worm.

The bobbit worm, or sand striker (Eunice aphroditois), is an aquatic predatory bristle worm that ranges from 4 inches to 10 feet in length and lives in burrows it creates in the ocean floor. The bobbit worm takes its name from the Lorena and John Wayne Bobbitt case, in which Lorena cut off her husband John Wayne’s penis with a kitchen knife.

Living mainly in the Pacific Ocean, bobbit worms hide in long, narrow burrows in the seafloor and propel upward to grab unsuspecting fish, large molluscs and other worms, before dragging them, still alive, back to their dens.

In the study, published in the journal Scientific Reports, the report authors note that the retreat of an ancient worm and prey into the sediment could have caused the “feather-like” structures preserved in Pennichnus formosae.

They identified a high concentration of iron at the top section of the burrow, and believe the worm could have secreted mucus to reinforce the burrow wall.

“We hypothesize that about 20 million years ago, at the southeastern border of the Eurasian continent, ancient Bobbit worms colonized the seafloor waiting in ambush for a passing meal,” the report authors wrote.

“When prey came close to a worm, it exploded out from its burrow, grabbing and dragging the prey down into the sediment. Beneath the seafloor, the desperate prey floundered to escape, leading to further disturbance of the sediment around the burrow opening,” they described.