Pelecypod ID

[minnbuckeye]

I am trying to make it a habit to ID and label my finds much better than I used to. So I ask for help on these "lowly clams".  I have tried to identify these 2 different pelecypods found on a trip back from Ohio at Thanksgiving. But my research is not proving fruitful. One specimen is very thin, the other broad based. They were found in a roadcut on Hwy 20 in NW Illinois in a very narrow (12 inch) band of rock, almost like hardened mud. This band was full of pelecypods but nothing else.. It likely was from the Galena formation of the Ordovician. I have found Ambonychia (Cincinnatian)as a similar pelecypod but one seems  too thin, the other seems too wide. Any clam experts???

 

 

[Tidgy's Dad]

There are many different species, some are more rounded and others flatter. 

The first one has been a bit compressed, I think. 

I would say they are both Ambonychia sp. but I am not a pelecypod  expert. 

Or an anything expert for that matter. 

[piranha]

Pojeta, J. (1966)

North American Ambonychiidae (Pelecypoda).

Palaeontographica Americana, 5(36):131-241  LINK

 

[minnbuckeye]

6 hours ago, piranha said:

Pojeta, J. (1966)

North American Ambonychiidae (Pelecypoda).

Palaeontographica Americana, 5(36):131-241  LINK

 

 

Wow, a treasure trove of info!!!

[Sagebrush Steve]

10 hours ago, Tidgy's Dad said:

Or an anything expert for that matter. 

Don’t say that @Tidgy's Dad, you seem to know your tortoises. 

[Tidgy's Dad]

Just now, Sagebrush Steve said:

Don’t say that @Tidgy's Dad, you seem to know your tortoises. 

Thank you. 

I do indeed know quite a lot about tortoise care. 

But not so much about pelecypods. 

Except we shouldn't call them bivalves anymore. Or something.