Found this fossil recently while visiting the Fossil Park near Rockford, Iowa. The fossils here are Devonian in age, and belong to the Hackberry Group/Lime Creek Formation. Have found numerous varieties of brachiopods, horn and colony coral, gastropods, bryozoa, and pieces of crinoid stems, but have never seen anything quite like this. Since it was such a crappy day, I had the whole park to myself except for one guy from Minnesota. Thinking he might be more knowledgeable than myself, I asked for his opinion on what he thought this was. He suggested it was definitely a crinoid calyx. I am not so sure.
Thank you all for checking it out.