Ocean-going Crinoids 

Those well known fossils, crinoids, are often found attached to, what are now, small pieces of coal. Originally these were pieces of driftwood.

Fossil crinoid attached to coal

William Buckland (and very possibly, Mary Anning) suggested that the crinoids had been attached to pieces of driftwood while alive, living suspended underneath it. For many years this was thought to be an impossibility - the weight of the crinoids would have caused the driftwood logs to sink.

But the author of THIS ARTICLE, and his co-workers, using many different sorts of advanced techniques, has worked out that crinoids do indeed hang suspended underneath the driftwood but clustered towards one end of it. Such a log could drift for ten to twenty years.

So now we know! The original article is HERE

Artists impression of a crinoid raft.