This fossil remnant is the most interesting find I had from a field trip to Franklin County, Kentucky (about 55 miles or 88 km east of Louisville, Kentucky). I think it was found in the Lexington Limestone and is from the Ordovician Period.
It might be part of a carpoid. It also could be part of crinoid calyx. Either way this seems to be a pretty rare fossil for the Ordovician Period layer I was looking at. The plate segments somewhat remind me of a turtle shell.
The fossil fragment is in a larger rock that contains Isotelus trilobite pieces, small branching bryozoa, some type of spiral gastropod, and pea size brachiopods.
Learn more about carpoids found in Ordovician rock at the Dry Dredgers website.
UPDATED: Dr. Colin Sumrall from the Department of Earth and Planetary Sciences at The University of Tennessee Knoxville identification of this fossil fragment as a rare carpoid Stylophoran Enoploura. Learn more about carpoids at this website. A big thank you to Dr. Sumrall for taking time to look at the fossil images!