These images are of a fully intact Eucalyptocrinus elrodi crinoid calyx fossil. It was found in the Waldron Shale of Shelby County Indiana USA. Fossil species is named after Dr. Moses Newton Elrod (1838-1907) a physician from Hartsville, Indiana who happened to like to look for fossils. He is credited with being the first to recognize the two layers of Indiana's Niagara formation: Waldron and Osgood.
There is an informative article about how Indiana doctors in the 1800s contributed to the knowledge of the states geology and paleontology. Entitled The Indiana Physician as Geologist and Naturalist by William DePrex Inlow published in Indiana Magazine of History Volume 56, Issue 1, pp.1-35 (1960). It was adapted from a speech the author gave at the Indiana State Library on December 11, 1947.
Read at this Indiana University web site: http://scholarworks.iu.edu/journals/index.php/imh/article/view/8681/11075