Mystery Critter II: Late Pennsylvanian brain buster

[LabRatKing]

OK gang, this one has me stumped.

This is the last specimen from last year's final trip to the Kiewitz shale, Stoner Limestone, Stanton formation along the Platte River in Cass County Nebraska.

 

I thought at the time, and until a few hours ago, that this was one of the disc shaped oncolites that have been found at that site and related sites in the area.

I was playing with a recently LED upgraded microscope and found it had cellular structure barely visible. so I decided to do a laborious prep on it with a bicarb blast.

 

It is in fact nothing I have ever seen before and is very fragile. Frustratingly, when I stabilized the fragile little thing, it made the structure less visible.

 

So, I had to get creative as I realized too late all my scope cameras and adapters are sitting on my desk at work...

 

Anyway, I have no clue what this is. the simplest solution is a disc shaped bryozoan, but the more I worked on identifying it, the less convinced it is within my skill level to identify.

 

So, here we go:

 

[LabRatKing]

And here are some micro photos at roughly 40x I totally hacked my way through to bring out the structures:

 

[LabRatKing]

And here it is back lit:

 

[LabRatKing]

And here is the flip side:

 

[DPS Ammonite]

Consider that it might be a Late Pennsylvanian sponge. The fine netting reminds me of sponge more than coral or bryozoans. See any spicules?

Edited February 16, 2021 by DPS Ammonite

[LabRatKing]

1 hour ago, DPS Ammonite said:

Consider that it might be a Late Pennsylvanian sponge. The fine netting reminds me of sponge more than coral or bryozoans. See any spicules?

That is a possibility that did not cross my mind. I'll have to take it to work to look for spicules as my fossil appropriate scope here at the house is only 2x-4x with 10x oculars.

[Missourian]

It looks like a budding colony of encrusting bryozoan with calcite-filled pores.