bryozoa or brachiopod?

[Ramona]

This is an odd little rock that I found at my son's land in Franklin County today, near Lost Creek (Alabama).  I am seeing what I think is an area of bryozoan fossils of some sort on it, but then I saw this tiny little shape that is encased inside of something else.  I thought it was a brachiopod at first until I looked up closed with my trusty macro lens and saw teensy dots along the edges.  Is this another type of bryozoa? And, if so, why is it encased inside of something?  
 

Thanks!!

Ramona

[Tidgy's Dad]

I think they may be brachiopods that have been broken and the broken off piece forced inside of the rest of the shell. The pinpricks could be spine bases, suggesting productids as the most likely type. 

[Ramona]

2 minutes ago, Tidgy's Dad said:

I think they may be brachiopods that have been broken and the broken off piece forced inside of the rest of the shell. The pinpricks could be spine bases, suggesting productids as the most likely type. 

Okie, that sounds likely to me!  Thanks!