After finding a great Sea Pen example, I also found this one that had been set aside. The specimen passes through the rock, therefore showing itself on the other side as well. A Crinoid stem impression can be seen on the opposite side.

The first one I found was supposed to be Pteronites, as indicated in the Pennsylvanian Bivavle Publication from Ohio. However as I understand it today, Pteronites is not a pinnid genus. It could be Aviculopinna?, however, it seems that this will not be a genus that occurs in the Pennsylvanian. A long story short, this particular specimen will likely be assigned to a different genus in the future due to work happening elsewhere.

A pinnid fossil, perhaps Aviculopinna?