In Desperate Need Of A Shell I.D. Please

[Tennessees Pride]

The title pretty much sums it up. I've reviewed every publication I can access, still having much trouble with what first appeared to me to be an easy I.D.

As you can see, the material has typical striated lines on its outer surface. On each striated line, there are "dots" from one end of the line to the other. Horizontally, the dots match up with the dots on the left and right of the striated lines beside. It would seem identifiable to me based on that type morphology, but I just can't find an example with such morphology.

Please help with this tough I.D. and thank you all in advance for viewing the specimen.

[Tennessees Pride]

Recovered from a Late Cretaceous Campanian time period.

[Tennessees Pride]

Two more views.

[Tennessees Pride]

I would consider, this may be a freshwater species.

[PFOOLEY]

Glycymeris?

[ashcraft]

I think you are looking at an internal cast, so what you are trying to compare on the outside, is actually the inside.

Brent Ashcraft

[Tennessees Pride]

Brent, i considered the same thing before, but gave up on that for lack of knowledge of any shell with an inside pattern such as that....the geometry of the dots are to precise. If it were true, I can't explain what use a shell would have with internal striations and dots....

Sir, do you know of any shell material that looks like that on the inside surface that I could reference?

As far as I can tell, the shell was replaced by an iron bearing mineral introduced to the sand through water, and cemented the sand, while replacing organic material.....there are also trace fossil trackways on the same surface of this material. So I honestly don't think its a internal cast.

Edited February 2, 2016 by Tennessees Pride

[Raggedy Man]

I also thought it might be an internal cast. But like you stated, the surface seems too textured. I think PFooley has come up with an ID. It looks dead on to me.

Best regards,

Paul

[Tennessees Pride]

Glycymeris?

I also thought it might be an internal cast. But like you stated, the surface seems too textured. I think PFooley has come up with an ID. It looks dead on to me.

Best regards,

Paul

Mike, that eye you have amazes me! Your suggestion is startlingly similar! Thank you very kindly. I don't quite know yet if that type occurs in the cretaceous, am studying up. The things I call dots may in fact be the growth rings as the shell grew, and because of the mode of preservation, now they appear as dots??? Not quite sure, but would be apt to believe something like that.

Paul, how bout that! I certainly agree Mike's suggestion looks uncannily similar!

[Tennessees Pride]

Boom!!!!!

History, habitat, and description all look good to me, I see no problems with PFooley's expert suggestion. Thank you so much!