Chesapecten ID

[dwsampson]

Is there a good rule of thumb, or simple method to distinguish between Chesapecten jeffersonius and C. madisonius?

 

[ClearLake]

Check out this post from a couple of years ago.  It has info on Chesapecten and several links that may be helpful.  If @MikeR jumps on, he may be able to summarize the difference more briefly.

[dwsampson]

Thanks for your reply. Sounds strange, but it's good to know that there is no simple answer. I'll try and post some pictures and locations a little later.

 

[MikeR]

In general, C. madisonius has more ribs than C. jeffersonius, but not always.

[dwsampson]

Thanks, seemed that way, but I wasn't sure if that was a reliable feature. Your input is helpful. 

[hemipristis]

17 hours ago, dwsampson said:

Is there a good rule of thumb, or simple method to distinguish between Chesapecten jeffersonius and C. madisonius?

 

also 

"Miocene and Pliocene Pectinidae From the Lee Creek Mine and Adjacent Areas" by Thomas Gibson, in Geology and Paleontology of age Lee Creek Mine, North Carolina, Vol. II.  Smithsonian Institution Contributins to Paleontology No. 67.  1987.

[hemipristis]

12 hours ago, dwsampson said:

Thanks for your reply. Sounds strange, but it's good to know that there is no simple answer. I'll try and post some pictures and locations a little later.

 

Pliocene scallops are a splitter's dream