This fossil appears to be a Platyceras dumosum (Conrad, 1840) spiny snail (gastropod). It was found in 2020 in Clark County, Indiana USA. The layer it was found is called the Jeffersonville Limestone which dates to the Middle Devonian Period.
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 Kenny for the picture.
