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.
Amazing specimen! I’ve never seen one like this. How does the color give indication of when it was collected?
ReplyDeleteIf you do a search (box in top left corner if using a web browser) on this blog for platyceras, you will see lighter colored specimens being collected. I am just guessing as to the age of this fossil but after going to so many museums and seeing the older collected fossils, they tend to be darker (not sure why, dirt from being handled, exposure to atmosphere). I have no science to explain my color speculation, just a personal observation that could be wrong. Also it was frowned up on to collect fossils from the Falls of the Ohio area (now it is illegal) so I am guessing no museums would get specimens after 1980-1990s. I contacted Dale who has this fossil now. He told me the specimen was bought from a collector who obtained it from the Michigan School of Mines in the 1940s when they got rid of their fossil collection. So this fossil was collected at least over 80 years ago.
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