Coiled Crinoid Holdfast/Arm

At first glance, this fossil looks like a coiled up millipede or some sort of worm. This coiled crinoid holdfast was probably used by the creature to anchor itself on the seafloor so it would not float away. It was found near railroad tracks in Indianapolis, Indiana. If I had to guess, it is probably from the Mississippian Period.

Thanks to Daniel for sharing this picture.