I have found one specimen that I can ID as belonging to the Genus Longispina and that specimen was found in the Mahantango formation. Below is a specimen I purchased as part of a lot from E-bay that comes from the Silica Shale in Paulding, OH. The label indicates that it is Longispina lissohybus but the shell is missing the tell tale spines that normally extend from the hinge line on the left and right sides. The radial ribs that decorate the surface are a bit muted as well so I'm not sure if this really is L. lissohybus. Interestingly, there appears to be a predatory gastropod boring on the pedicle valve.
The Silica Shale is Devonian (Givetian stage) in age.