Queen of Decay

The January 2009 issue of Science has an article about Osedax, an annelid worm with help from Oceanospirillales bacteria, feeds on the bones of whales. 

It notes how the male worms are parasitic on females and "thus fertilization is guaranteed." 

The females from a swimming trochophore [A trochophore is a type of free-swimming planktonic marine larva with several bands of cilia] only occurs when the larvae encounter a carcass and have been infected with the endosymbiont. 

Interestingly enough there is an article in the December 2008 edition of National Geographics about Pilosaurs, that were big as school buses and looks like precursors to whales. They lived in the Jurassic Period, were 50-feet-long and found 400 million miles from Norway's Coast. I would bet that Oceanospirillales feasted on these and had plenty of time to diversify to adjust around the world.