An eroded crinoid stem from Lake Cumberland, Kentucky. The image contains a variety of different views. This crinoid was from the Mississipp...

Here is a cephalopod segment piece and trilobite head from the Devonian Period found in Clark County, Indiana.

Here is a small cephalopod mold about 2 cm across. A siphuncle can be seen in the center of this mold filled with calcite or quartz. This ce...