UPDATE: I am pretty sure my earlier identification is incorrect. I now think this might be an Elphidium aculeatum ( Polystomella aculeat...

This piece of Devonian Period limestone is from the Jeffersonville layer of Clark County, Indiana. It is unique in that it contains spines...

Enrolled  Flexicalymene meeki trilobite fossils found in Franklin County, Indiana. These creatures scurried along the sea floor back in t...