Cross section of Ordovician Cephalopod

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 cephalopod was found in eastern Jefferson County, Kentucky. It is from the Ordovician Period.

Diamond Cut of Colonial Coral

Here is a view of two sides of the colonial coral. This one was found in eastern Jefferson County, Kentucky. It is an Ordovician coral.

Grewingkia canadensis Horn Coral

Here is an Ordovician horn coral found in eastern Jefferson County, Kentucky. I sliced off the top part that was covered with debris using a diamond saw. You can see the borings of probably a worm. The image shows the top few that has been polished with wet sand paper and the side view showing multiple boring marks.

See this neat website on bioerosion (http://www.wooster.edu/geology/Bioerosion/Trypanites.html) by a worm like creature called Trypanites. Boring marks are seen quite a bit on horn corals but I rarely find them going through to the septa. This one did but I should have preserved the distal end to see if it was more a rounded or flared.