Bore holes?

[JBGood]

I am a novice.I live in south western Ohio (Ordovician). I have some acreage and lots of hills and creeks. I have been picking up what look like sedimentary rocks and many are loaded with marine fossils. The photos below show a piece of soft rock (sandstone I think, maybe shale?) with apparent bore holes (photo 1). I whacked this piece along the edge and a chunk popped off and some brown stuff was in between the layers (photo 2, close up photo 3). 

 

Are these spots the remains of the critters that made the holes in the surface of the rock or just some brown gunk? Under magnification the U-shaped brown blob on the left in photo 3 appears to be segmented. 

 

Any comments would be greatly appreciated. Thank you!

[Plax]

aulopora?

 

[Fossildude19]

Looks like infilled burrows, to me.

The meniscate looking backfill puts me in mind of something similar to   Beaconites barretti.

 

 

      

 

 

Neat find.  

Regards, 

[TqB]

I agree with Tim.