Bone-munching "zombie" worms are eating our whale fossils

After a dead whale falls to the bottom of the ocean, thousands of marine organisms will carve out a home in its carcass. Among these corpse squatters are the Osedax, a genus of marine worms that bores into whales' bones and feed on the delicious cetacean fats inside.

The physiology of these Osedax "zombie" worms is wonderfully gruesome — the mouthless, stomachless worms dig a cavity in the bones and insert themselves like tiny disgusting blades of grass. And even though the Osedax genus was first discovered in 2002, British researchers have now harnessed scanning technology to discover evidence of these bone-eating worms on a 3-million-year-old whale fossil.

The researchers discovered these canals on a fossil that was disinterred in 1875. Explains Marine biologist Nicolas Higgs of the University of Leeds and London's Natural History Museum:

The team studied borings in a 3-million-year-old whale bone fossil from the Mediterranean in Italy, which they thought may have been made by Osedax worms. They used the Museum's micro CT (Computed Tomography) scanner, which can reveal incredible detail and accuracy, in 3D, without damaging a specimen.

They compared the borings with those made by living Osedax worms and other animals such as bivalves and other marine worms. [...] Higgs explains the research, ‘At first I was sceptical, but the more I investigated the borings the more confident I became that these borings were caused by Osedax, so it was a slow build up of excitement.

When coupled with a prior discovery of Osedax on 30-million-year-old Pacific fossils, this new find further suggests that these zombie worms have been dissolving the marine fossil record for a good long while:

‘Our results tell us that Osedax worms were very widespread throughout the world's oceans in the past and so may have had a significant negative effect on the global fossil record of whales, since they were destroying the bones,' says Higgs.

Also, Osedax worms aren't found in the Mediterranean nowadays, so the Osedax's marine habitats could've been even more widespread centuries ago. Sure, Osedax was likely chowing down on museum-worthy whale bones for millennia, but it's also pretty nifty to discover evidence of some foul little invertebrates that don't fossilize particularly well.

[Historical Biology via The Natural History Museum]