A new study has found that a type of bone-gobbling worms are currently spending its days nibbling through the skeletons of dead whales that has actually been around for at least 100 million years.
According to research, these tiny, thread-like worms used to dine on prehistoric marine reptiles, such as plesiosaurs, and thus may have also left a dent in the fossil record. The bizarre, finger-length worms called Osedax Worms are soft-bodied and leave no fossils behind, so their origin is lost to time. But traces of the creatures’ strange dining habits can be detected on ancient fossils.
Since these worms are known for feeding on the bones of dead whales, or falls as they are called, it was assumed that these animals probably evolved at the same time when the ancestors of whales transitioned from land to sea. But some researchers proposed that they may have appeared much earlier than that, possibly feasting on ancient marine reptiles which roamed the seas during the time of the dinosaurs.
Osedax, On the other hand, not only feast on dead whales today, the worms also bored into 100-million-year-old plesiosaur and sea turtle bones!
To find evidence for this idea, researchers from Plymouth University scrutinized the 100-million-year-old fossilized remains of a sea turtle and a plesiosaur’s flipper using a CT scanner, which created detailed computer models of the skeletons. The resulting 3D images revealed the presence of distinctive bore holes and cavities which were characteristic of the burrowing technique employed by Osedax today.
This suggests that Osedax did not in fact co-evolve with whales, but instead have been around at least since the early Cretaceous period. And when plesiosaurs became extinct during the Cretaceous-Tertiary mass extinction event, which wiped out the dinosaurs 65 million years ago, that there were distinctive round boreholes and rootlike cavities in bones from turtles and plesiosaurs (bus-size, flippered marine reptiles). These worms turned their attention to sea turtles and made a living off of them until whales came on the scene.
Alongside pushing back the date for the appearance of these unusual animals, these findings have implications for the fossil record as they may have prevented many skeletons from becoming fossilized.
By destroying vertebrate skeletons before they could be buried. Osedax may be responsible for the loss of data on marine vertebrate anatomy and carcass-fall communities on a global scale,” explains lead researcher Silvia Danise,
Bone-eating worms are amazingly effective eaters for creatures with no mouths or guts. However, how the worms eat remains a mystery, but scientists think the creatures extend fleshy tendrils laced with symbiotic bacteria into the bone. The tendrils carve through the nutrient-rich tissue and extract collagen and fat with help from the bacteria. This eating action leaves behind an empty pocket that resembles a tree stump with roots.
via Plymouth University and Biology Letters