
My first spiny snail fossil find in the Devonian Period Jeffersonville Limestone of Jefferson County, Kentucky. The fossil could be a Platyceras dumosum? (Conrad, 1840). It is somewhat weathered but some of the bumps can be made out where spines once existed.
Next image is from the book Kentucky Fossil Shells - A Monograph of the Fossil Shells of the Silurian and Devonian Rocks of Kentucky by Henry Nettelroth, 1889, Frankfort, Kentucky, Kentucky Geological Survey, Plate XXIII, Figure 2 of the Platyceras dumosum (Conrad, 1840).