ID help on two finds

[nathead]

Hello,

 

I have a few specimens my kids and I have found and need help identifying, if they are indeed fossils.  I included a dime for size reference, but will try to include a measurement also for each:

 

The first two images are a swirl shape in rock (I was hoping it was a shell) about 4 centimeters across

 

The next images are of two round things (1.5 and 2 cm across) embedded in a rock, there are crinoid stems embedded near them

 

All were found in Hamilton county Tennessee.

 

Thank you for any info

 

[Fossildude19]

I'm  a bit surprised no one has commented on these.

 

The first item looks like a gastropod steinkern.

The second - not sure. Could be some weird preservation of crinoid calices, poorly preserved brachiopods, ... or concretions.