This fossil is very strange, just looking at it I would identify it as a horn coral but it is a brachiopod. The label in the museum listed it as "tütenförmiger Armfüßer" which translates to bag-shaped brachiopod. Learn more about this fossil at the blog Equatorial Minnesota and its relation to Benjamin Franklin Shumard (1820-1869) at medical doctor from Louisville who switched to paleontology. This fossil might be under the genus Prorichthofenia now.
https://equatorialminnesota.blogspot.com/2018/03/prorichthofenia-brachiopod-horn-corals.html
