Wednesday, May 6, 2020

Cypricardella tenuistriata pelecypod from the Moscow formation

Today I have a complete specimen of the pelecypod Cypricardella tenuistriata to show off. It has both valves and is well articulated with out distortion. C. tenuistriata is a rectangular shaped shell with the anterior having a small rounded appearance and then a straight edge back to the umbo. The Posterior is largely rounded but boxy. There is a straight hinge line along the top margin of the shell while the bottom margin is broadly curved. the surface of the shell has a weak ridge extending from the umbo to the posterior margin and thin growth lines decorate the surface.

Right valve
Left valve
Top margin
Bottom margin
A closer view of the right valve. You can see the concentric growth lines along with what looks like   borings of the shell by some creature. Perhaps a sponge or worm?

Compare this specimen to one from the (older) Panther Mountain formation.  Or this one from the Moscow formation along the Lake Erie shoreline.

This specimen was found at a borrow pit on Deep Springs Road in Madison County, NY which exposes the Windom shale member of the Moscow formation (middle Devonian in age, Givetian stage.) 

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