Plumulitids were annelid worms - the group including earthworms, bristleworms
and leeches, today found everywhere from the deepest sea to the soil in your yard.
Levin's group is studying bristleworms
, in particular why so many from the family Dorvilleidae inhabit these seeps (17 species so far, including 10 in one genus).
This change, in turn, is likely to restructure the foodweb, since mussels are an important prey item for many fish that won't eat bristleworms