Donating to the museum
In New Horizons
When donating to Blathers or selecting "Tell me about this!" in New Horizons, he will provide the following information about the fossil:
"The myllokunmingia! Said to be one of the oldest fish-like animals, it lived well before the dinosaurs. It was about an inch long and seems to have had no lower jaw. It is awe-inspiring imagining such ancient life! There is much we still don't know. We may yet discover even older organisms with even fewer jaws!"
The Myllokunmingia can be found in the first room of the fossil exhibit in the museum.
Myllokunmingia is one of the earliest chordates found. It lived in what is now southern China from 535 to 520 million years ago. Only one specimen is known, measuring 28 mm long and 6 mm high. It is hypothesized to be a vertebrate, although this has not been firmly established.
More information on this topic is available at Wikipedia.