Here are some pictures I found from a trip in March 2008 to a road cut in Crawford County, Indiana. It is a fun place to hunt for fossils from the Mississippian or Lower Carboniferous period. You will need to do some climbing though.
Unknown trilobite pygidium found in the Indian Springs Shale of the Big Clifty Formation in Crawford County, Indiana.
UPDATE (2020/02/15): Maybe a Kaskia chesteriensis or Paladin chesteriensis.
Unknown horn corals from the Mississippian period.
UPDATE (2020/02/15): Maybe a Zaphrentites spinulosa or Amplexi zaphrentis?