A very long time to be around

plesiosaur from Wikipedia

Are Gross, Whalebone-Eating Worms Actually Older than Whales?
[Via Discover Magazine]

If ever a species got the disgusting name it deserved, bone-eating worms would be the one. Robert Vrijenhoek’s team discovered them five years ago eating the bones of a dead gray whale off California, and since then they’ve shown up in whalebones around the world. The worms don’t have mouths or anuses—instead, they rely on their bacteria to handle nutrient uptake and waste disposal. And according to a new study by Vrijenhoek in BMC Biology, there’s more to these strange sea-dwelling scavengers: They might have been around since before whales even existed, and are probably more numerous than we thought.

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Perhaps they were once plesiosaur-eating worms? Someone check out some fossils.

They have some pretty disgusting scientific names, also. The Monterey Bay Aquarium has more.