Ecology and Life History of the Crinoidea
These crinoids, from the Lower Jurassic Posidonia Shale of Germany,
were growing on a floating piece of wood that was buried intact along with
its occupants. Stalked crinoids, then as now, lived attached to a substrate -
rock, sediment, or wood. These are over a meter long, and are on display
at the Senckenberg Museum in Frankfurt, Germany.