This flightless dragon species extinct after the arrival of the first humans in New Zealand, the first corpse which was found came into the hands of Gideon Mantell.
He died before he could publish his discovery, and the ancestors of the neoraptors hide the specimen and his notes from the public.
Here you can read more: [link]
The Mantell-specimen (gray shape) was a young, not fully grown male. How the scientists of the Institute of supposed fictional Biology later discovered is Dinodactylus a species with a very intersting allometric scheme. The juvenile had bigger wings a shorter snout and more robust tail fan.