Pelecypods are usually not very well preserved in the Windom shale but the below specimen is an exception. It is a valve from a Pseudaviculopectin exacutus that still has some replaced shell material present.
The calcite that replaced the shell is very thin and delicate and some of it was removed when I was lightly cleaning it with a toothbrush. I'm leaving it as it for now and will likely coat it with a thin layer of PaleoBond to help preserve it. The specimen was found at the Penn Dixie site in Blasdell, NY within the Bayview coral bed of the Windom shale (Devonian, Givetian stage) mbr. of the Moscow Formation.