Wood or Coral fossil ID

[Betsy5758]

New to fossil forum - 2nd post. Spent considerable time & have thoroughly enjoyed reading posts requesting id’s!!! 
I found this fossil (& 2 others exactly the same but considerably smaller - same fossil hunt) loose in a St Louis, MO county mostly dry creek bed.

Online research consensus was coral fossil. But, it looks like pet wood to me. Not apparent in pics, but the rock sparkles with quartz druzy that I’ve found to be common in the rocks I’ve collected from Northeast & Southeast Missouri.

[debivort]

This might be a "styolite" formation.

[Betsy5758]

Did some online research on stylolites. VERY interesting! Read one article / post from guy in Michigan saying, you think you’ve found a wonderful piece of pet wood … nope it’s a pet wood imposter - a stylolite!

Ty to debivort for steering me in correct direction!!!