Fern fossil

The Fern Fossil is a stand-alone fossil that can be donated to the museum in, , and.

In
"Hoo, a marvelous find! This fossil is in absolutely tip-top condition! This piece of fauna had just emerged from the sea when it became preserved. Rather than seeds, it relied on its spores to spread. It resembles moss with leaves! Ah! Terribly sorry, wot? Ancient plants turn me into a veritable hootbox!"

In Real Life
Fossilized fern is what makes fossil fuels and it is basically term that had been compressed over millions of years.

In New Leaf
"Originally, all plants on the planet were actually sea dwelling, but then they eventually spread to land. This fossilized fern is thought to be one of the very first plants to make this move to dry land. Reproducing via spores rather than seeds, it resembles modern ferns, though several yards taller."