Crinoid Graveyard Piece

Here is a rock slab I saw at the last KYANA fossil study session. It was probably at least 30 cm long and full of broken crinoid stems.

I saw in the KYANA display case something like this and it was called a graveyard rock.

It looks like crinoids seen at Lake Cumberland so I would say this is Mississippian period, just a guess. :)