Pennsylvanian Bivalve Help Needed

[historianmichael]

I recently visited an exposure of what is likely the Brush Creek section of the Glenshaw Formation, Conemaugh Group (Late Pennsylvanian) in Western Pennsylvania. I brought home a large block of material that I subsequently broke down. I was excited to find in the block a nice Worthenia tabulata, several smaller gastropods and even a fragment of the nautioid Metacoceras. I also found this large bivalve. I tried to cross reference this fossil against lists of fauna from the Brush Creek and while it strikes me as similar to Edmondia sp., I am not that confident, especially given the size. When searching in the Brush Creek I have typically only ever found the common, small bivalve Astarella concentrica, so this much larger bivalve has me stumped. Any help is greatly appreciated.

 

 

 

[connorp]

The past couple weeks I have been identifying Pennsylvanian bivalves from a new (to me) formation. I don't recognize your bivalve, but here are some resources I have found to be very helpful. The Pennsylvanian Atlas is a great starting point for Pennsylvanian IDs in general, and once you have a possible ID, there may be some good comparative images in the Yale collections.

https://pennsylvanianatlas.org/classes/bivalvia/

https://collections.peabody.yale.edu/search/

[Thomas.Dodson]

Paleozoic bivalves can be a real pain to identify, largely in part because they take a backseat in studies to brachiopods which are more important as stratigraphic index species. That said, the general characteristics seem like a good match for an Edmondia sp. and they do get that large (and larger) so I think you're on the right track.

[Zenmaster6]

I saw this and immediately guessed Edmondia as well. I was just studying them the other day, reading my fossil books. 

 

I spent the last 10 minutes scowering the internet for a photo of one that looked like yours but Thomad.Dodson is right. 
There isn't anything about carboniferous bivalves online.