This fossil is a
Platyceras dumosum (Conrad, 1840)
spiny
snail (gastropod). It was found at the Falls of the Ohio in Clark County, Indiana USA.
Fossils cannot be collected at the Falls any more but this one came from a de-accessioned museum collection in Michigan. The layer it was found is called the Jeffersonville Limestone which
dates to the Middle Devonian Period.
Judging from by the color this fossil might have been collected over 100 years ago.
The genus Platyceras was named by Timothy Abbott Conrad (1803-1877)
in Third Annual Report on the Palaeontological Department of the
Survey. New York Geological Survey, Annual Report 4(1):199-207 1840.
Thanks to Dale for letting me take these pictures.
