Penn Dixie Lunulicardium? Bivalve

[ClearLake]

Here is a quick and (hopefully) easy question for all you Penn Dixie (New York, Erie County) or bivalve experts out there.  In going through some of the material I collected last summer, I came across this very nice, but small (1.1 X 1.0 CM) bivalve.  It looks most like Lunulicardium eriensis figured on page 160/161 of Wilsons Field Guide to the Fossil of New York.  But the book lists it as from the Upper Devonian Canadaway Group and I can't seem to find any reference to it (after a quick search) from the Middle Devonian Moscow Group present at Penn Dixie.  My question is: is my ID incorrect or did I just not dig deep enough to find reference to it from Penn Dixie or the Middle Devonian?  Thanks for any help.  @Fossildude19 @Kane, @Jeffrey P and any others.

 

 

     

[Isotelus2883]

This looks more like a distorted brachiopod to me.

[ClearLake]

4 hours ago, Isotelus2883 said:

This looks more like a distorted brachiopod to me.

Interesting observation and could be.  My main problems with that are:

- I think I see a lunule developed on the part just below the beak on the right side and it fit so nicely with the description and picture in the book.  The potential lunule is not very obvious in the pictures, but is more evident in person.   The right side is much steeper than it appears in the first picture above.  I have since done some more online searching and found that Lunulacardium (this spelling is the correct one according to a 2007 paper that revised the family) is not a very well studied genus but I have seen numerous examples that look pretty similar to this one.   

- Second, I thought the shape of the anterior margin was not "brachipod symmetrical" (even taking into account the potential folding) but in looking at it some more, I not sure now. 

- Third, I'm not sure I see a brachiopod that is a good match for an unfolded version of this, especially the beak/umbo area.  One of the Rhipidomellas is possible, I suppose.  I'll have to see if I have a similarly sized Rhipidomella that I can compare.  What brachiopod were you thinking of?

 

Probably what I need to do is see if I can prep away some of the matrix around the beak/umbo and see if I can get a better view.  But without being able to see the hinge, that will most likely not be definitive either.

 

Thanks for your thoughts.

[Fossildude19]

7 hours ago, ClearLake said:

It looks most like Lunulicardium eriensis figured on page 160/161 of Wilsons Field Guide to the Fossil of New York.  But the book lists it as from the Upper Devonian Canadaway Group and I can't seem to find any reference to it (after a quick search) from the Middle Devonian Moscow Group present at Penn Dixie. 

 

 

I have that problem with Wilson's Guide.  I find what I'm pretty sure are Paleopinna flabella in at Deep Springs Road in the Middle Devonian, and Wilson only lists them in the lower Devonian Tristates Group.

 

That said, yours looks a bit more like Paracardium doris, to me.  (Pages 158 and 159)

 

 

 

Also, Panenka sp. is another possibility, in my opinion.

 

 

 

 

 

 

[ClearLake]

18 hours ago, Fossildude19 said:

That said, yours looks a bit more like Paracardium doris, to me.  (Pages 158 and 159)

 

Well that is an interesting suggestion as well.  And silly me, I totally spaced out on looking through Linsley's book!  Much more to choose from there, thanks.  I'm afraid the angle of my first picture may have made the shell look more oval/round than it looks in person, where it is more triangular in shape.   I think it was how I tilted it under the camera and since it is in a small block of matrix, its a little tougher to find the "laid flat, straight down" orientation.  And, as always, being able to see the hinge teeth would probably really narrow the choices.  Thanks for the help.