My gradually expanding Warsaw Formation collection

[Vindola]

Here are a few highlights from the things found on my trips exploring Mississippian sites from the Warsaw Formation. These items were found in St Louis and Jefferson Counties, Missouri. From the top:

 

1. Several crinoid calyx pieces.

 

 

 

2.  The bottom or “cup” of a calyx. I found a similar one still in the rock but had no tools to remove it. 

 

 

 

3. A hash plate with what appears to be the internal mold or steinkern of a brachiopod: it looks similar to Leptaena but as far as I am aware that genus went extinct several million years before this formation. A relative perhaps?

 

 

 

 

4. Another hash plate, with what appear to be the remains of a crinoid holdfast! If so it is the first reasonably intact one I have found.

 

 

 

 

5. A hash plate, with bryzoan bits, crinoid columns and what appears to be one of the very few pelycopods I have found in this formation. 

 

 

 

 

6. A mostly-complete brachiopod valve, possibly a productid due to its shape. It has been squashed flat by pressure.

 

 

 

 

 

7. One of my favorite hash plates from this formation, with crinoid sectionals of several species, calyx plates and a partial neospiriferid brachiopod.

 

[Coco]

It would be more convenient to put the text above or below each photo concerned, because in this case we are forced to scroll to know what you’re talking about

 

Coco

[Vindola]

I apologize for the inconvenience: I am currently having technical difficulties with the website and my laptop and had to use my phone to submit these. I will keep that in mind going forward. Thank you!

[Mochaccino]

What does the other side of the second specimen look like? It resembles the infrabasal disk of a stemless crinoid known as Staphylocrinus, but I have not heard of that genus being found here, much less this early. It is typically a Chesterian crinoid. Are you sure you are hunting the Warsaw?

[doushantuo]

for those who like to know such things: 

the Chesterian ( "upper missisippian ") ranges from somewhere in the Visean2b to the Namurian H1 / H2 

edit: boundary

Edited November 20, 2024 by doushantuo

[Vindola]

The underside of the crinoid disk is very encrusted and does not photograph well but seems to have five raised lines radiating towards the center. I admittedly am not sure if it is the Warsaw as it seems to have more mud than the limestone at  the confirmed Warsaw site I’ve visited, but it is in an area with many outcroppings of the Warsaw and Salem formations and I was told by several more knowledgeable individuals that it was Warsaw.  I will note that I have found several calyx cups in the outcrop and they are always upside down.

[Vindola]

I apologize for the poor quality picture. No matter what I try the cup does not photograph well. I’ve tried different angles of lighting and am getting the same result. It may be that it is too small for the camera to focus on. 

[Vindola]

One other fossil from the site is this partial trilobite pygidium. It is the only post-Devonian trilobite I’ve ever personally found. It is most likely Kaskia but may be Pudoproetus based on the size of the fossil and the fact that it seems a bit wide to be Kaskia.

[Mochaccino]

16 hours ago, Vindola said:

The underside of the crinoid disk is very encrusted and does not photograph well but seems to have five raised lines radiating towards the center. I admittedly am not sure if it is the Warsaw as it seems to have more mud than the limestone at  the confirmed Warsaw site I’ve visited, but it is in an area with many outcroppings of the Warsaw and Salem formations and I was told by several more knowledgeable individuals that it was Warsaw.  I will note that I have found several calyx cups in the outcrop and they are always upside down.

Definitely not a Staphylocrinus at least that I'm aware of. Not sure what it's from but it is unusually thick and symmetrical. Might be a basal plate from some sort of ornate cladid.

[Vindola]

2 hours ago, Mochaccino said:

Definitely not a Staphylocrinus at least that I'm aware of. Not sure what it's from but it is unusually thick and symmetrical. Might be a basal plate from some sort of ornate cladid.

I found another similar looking one still in the rock which I had to leave behind. It’s an odd but rich site, with weird bits of phosphatic material and pennids alongside a plethora of horn coral, crinoid stems (including what appears to be Nipterocrinus) and Archimedes bryzoan screws.