New to fossil hunting...please help with this...

Hey.....I have slowed down metal detecting this year and have been spending more time arrowhead and fossil hunting. I found this and a whole lot more similar kind of things at my fathers in Caldwell County, KY. It looks like a backbone or something to me....but I really dont know. See the back side of this...it is full of neat things....there are some I have found that are full of this stuff and almost 2 feet long. I appreciate any thoughts....thanks!! Also.....just curious if this sort of thing has any value other than just being neat to find.

Could be the spirally-branching colonial bryozoan, Archimedes.  These are sometimes abundant in Mississippian limestone. 

Your limestone might be characterized as "encrinal limestone" because of all the crinoid parts.  Low collector interest unless you have the crinoid head.

I looked up the crinoid head...very interesting. As I said, I am very new to this....what part of this rock is what you said looked like part of a crinoid head? Thanks