Pennsylvanian fossils

[aek]

I found some time this past weekend while passing through to take a look at a small stream cut exposing cyclothem layers of marine limestone and swamp coal in east central Illinois. 

 

Here are some fossils I found from the marine rocks. Bond formation. Offshore sediments, deep water.

 

Ditomopyge sp. UV  

 

Lophophyllidium

 

Not sure what these are. These are magnified. Each one about the size of a grain of sand. Assuming they are crinoidal. Any help with ID appreciated.

 

Very tiny tooth measures <.5mm.  The acrodin cap is characteristic of an actinopterygian, but I don't know if it can be identified any further than that.

 

Thanks for looking.

Edited November 7, 2022 by aek

[Phevo]

6 hours ago, aek said:

Not sure what these are. These are magnified. Each one about the size of a grain of sand. Assuming they are crinoidal. Any help with ID appreciated.

 

 

These look like partially silified ambulacral plates from a regular sea urchin to me, but I don't know anything about the bond formation

Edited November 8, 2022 by Phevo

[aek]

@Phevo Indeed, that is an interesting observation. At the moment I can't find any information about echinoderms other than crinoids from this formation, but maybe I can dig a little deeper at school later in the week. I took another look at the residues that remained on my screen and found some spines that probably belong to these plates. They don't appear to be crinoidal or bryozoan so that is intriguing.

 

[Missourian]

It is wonderful to find silicified fossils in limestone. You never know what can turn up in the residue.

 

I've had pretty good luck in a Pennsylvanian limestone in Missouri:

 

 

[aek]

@Missourian beautiful finds!

[deutscheben]

Thanks for sharing! Those are similar to Bond Formation finds I’ve had from La Salle County (including urchin spines) but I haven’t encountered any down here in central Illinois yet.

[aek]

14 hours ago, deutscheben said:

Thanks for sharing! Those are similar to Bond Formation finds I’ve had from La Salle County (including urchin spines) but I haven’t encountered any down here in central Illinois yet.

Interesting,  have you by chance come across any papers with descriptions of urchins from this formation? 

[deutscheben]

The only formal reference I am familiar with is a 1931 thesis from the University of Illinois: Griffin, Judson Roy. The Fauna of the La Salle Limestone. Urbana, Ill. Unfortunately it is not available electronically, but I have read the print copy and it documents the presence of Archaeocidaris spines and plates from the deposit. 

[aek]

4 hours ago, deutscheben said:

The only formal reference I am familiar with is a 1931 thesis from the University of Illinois: Griffin, Judson Roy. The Fauna of the La Salle Limestone. Urbana, Ill. Unfortunately it is not available electronically, but I have read the print copy and it documents the presence of Archaeocidaris spines and plates from the deposit. 

Thanks for this information. After doing a search, it appears there is only a single copy of this thesis, but that will give me a reason to pop in to the library next time I'm in the Urbana area. There are some nice examples of Archaeocidaris online for reference.

[Tales From the Shale]

Love the pygidium! La Salle has members of Amuera that preserve to look very similar.

 

Also did you intentionally seek out those microfossils? Or was that by happenstance?

 

 

[aek]

I was looking for microfossils in specific layers..and trilobites.. however I wasn't expecting to find sea urchin remains, so this was a nice surprise.

[Tales From the Shale]

Interesting. I haven't even scratched the micro fossil world. I think I need to reconsider.

[Petalodus12]

Nice actinopt tooth! I'd agree that it can't be identified to anything more specific, as Carboniferous actinopterygian teeth are pretty conserved across taxa