When six-foot long ambush-predator worms colonised the seafloor
Researchers have found evidence that two metre long carnivorous worms roamed the ocean floor 20 million years ago. The finding came when scientists reconstructed an unusual trace fossil found off Taiwan that they identified as a burrow.
Burrows are what are known as trace fossils – preserved imprints left behind by the activities of ancient animals. Because the worms that lived in these ancient tunnels were invertebrates they didn’t have skeletons to leave behind in the fossil record, but what they did leave behind are tubes over six feet long and about an inch wide.
The diggers may have been prehistoric analogues of modern bobbit worms, known for burying themselves in sand to surprise and strike their prey. If ancient bobbit worms did terrorize the seafloor back then, their burrows are a rare example of invertebrates hunting vertebrates — usually it’s the other way around.
The presence of carnivorous worms also makes the ancient seafloor ecosystem of the area more complex than previously thought.