Researchers have discovered that so-called “zombie worm” called Osedax dates back to 100 million years ago. At the time the worm lived off the bones of prehistoric creatures like plesiosaurs and sea turtles. Knowledge about the worms is limited and they were not discovered until 2002, when they were found living on the bones of a decaying gray whale in the Monterey Canyon, at a depth of 2,893 meters.
The research group, operating from the University of Plymouth (U.K.), made the discovery by detecting remnants of Osedax on plesiosaur fossils. The finding is important in terms of establishing geological time.
Another interesting aspect is that there are probably fewer fossils today because the worms devoured so much bone, thereby preventing bone from becoming fossilised.
Osedaxs are the size of a finger and they are found worldwide throughout the seas, at depths of up to 4,000 meters. The worm is a member of the Siboglinidae family. These types of worms lack a mouth and digestive system. They “feed” by penetrating bone via root-like tendrils. Once they have burrowed in, the worms absorb bone collagen and lipids. These substances are transformed into energy by bacteria found inside the worm.
The main type of bone that the worms feast on are whale bones. The worms appear to have been associated with whales for 45 million years.
To reach these conclusions researchers studied a plesiosaur fossil unearthed in Cambridge, together with a sea turtle found in Burham, Kent. By using computed tomography scanners (three-dimensional X-rays) the scientists found bore holes and cavities that matched the burrowing method of Osedax.
The findings have been published in the journal Biology Letters. The article is titled “Bone-eating Osedax worms lived on Mesozoic marine reptile deadfalls.”
