From the Age of Crinoids or the Mississippian Period, this southern Indiana fossil is thought to be a Culmicrinus elegans. If the state of Indiana had an official state fossil it would probably be some sort of Mississippian Period crinoid.
This crinoid calyx fossil appears to be a Dasciocrinus florealis (Yandell and Shumard, 1847) found in the Mississippian Period rock of southern Indiana. Scale is in centimeters.