Wisconsin is probably not the first place you'd look for jellyfish, but a lot of them have been found there. Wisconsin Jellyfish on today's Moment of Science.
Researchers who study jellyfish were delighted when a whole bunch of them turned up in Wisconsin. They were found in a sandstone quarry. That is, these jellyfish were fossils--and when they died, what is now a quarry in Wisconsin was a lovely beachfront. It is puzzling to think that a jellyfish could fossilize.
These days it would be very rare indeed--one good reason being that a dead jellyfish on a beach is quickly eaten, or at least broken apart, by other animals. But when these jellyfish died there weren't many scavenger-type animals around.
These jellyfish were found to be four hundred and ninety-five million years old. And researchers could still see the thin impressions of their bodies. They could still make out the shapes of the jellyfish and, in some cases, their stomachs as well.