Pteranodon

The Pteranodon is a fossil that can be donated to the museum in all games to date. It is a three or four-part fossil, depending on the game - introduced a fourth part, the body, which was removed in.

In Wild World
Once you have donated all of the Pteranodon fossils, Blathers will say:

"The pteranodon was simply a wonderful creature. It emerged in the later age of dinosaurs, winging through the ancient skies. Though it could fly, it was most certainly not a bird! No, it was a reptile, wot! When it spread its wings, it was as big as a small airplane. Simply gargantuan! The very thought boggles my brain, to be honest. Ah. Hoo. Yes, so sorry. I'm actually rather glad the brute no longer exists."