Nautilus maximus (Conrad, 1838) cephalopod fossil found at the Falls of the Ohio, Indiana USA. It dates to the Devonian Period and was probably found in
the Jeffersonville Limestone. This image is from the 1889 Kentucky Fossil Shells by Henry Nettelroth in Plate XXIV figure 1.
This fossil is stored at the Smithsonian and was assigned catalog number: USNM PAL 51243.