A cousin found this coiled Silurian cephalopod in the Louisville Limestone last week. I think it is about 10 cm in diameter. Wow, I only find orthoceras (straight) cephalopods and even then they are rare finds in the Silurian rock. This one was found in Louisville, Kentucky USA.
This one might be a Lituites marshi (Hall) shown on Plate XXX Figure 1 in the 1889 Kentucky Fossil Shells - A Monograph of Fossil Shells of the Silurian and Devonian Rocks of Kentucky by Henry Nettelroth (1835-1887) at this University of Kentucky website (www.uky.edu/OtherOrgs/KPS/books/nettelroth/files/nettlerothplates.pdf).
