Friday, May 6, 2011
Not sure what this is, thought it might be some sort of crinoid calyx but cannot find where the stem attached. Reminds me of a brownish dinner roll or slightly deflated doughnut hole. It is about 2 cm wide and 1 cm tall embedded in matrix with a lot of Cryptolithus trilobite pieces. The brown material might be argonite. Matrix is the Kope Formation of the Ordovician period found in Carroll County, Kentucky.
Also included is a picture of a fragment of an Ambonychia clam fossil located on the same matrix block as this mystery fossil.