Parasaurolophus

The Parasaurolophus (known as the Parasaur in and, and the Parasaurus in ) is a three-part fossil in the  introduced in  that appears in all subsequent games to date.

In
When donating to Blathers in, he will provide the following information about the fossil:

The Parasaur can be found in the first room of the fossil exhibit in the museum.

In
When donating the final part to Blathers in, he will provide the following information about the fossil:

The Parasaur can be found in the first room of the fossil exhibit in the museum.

In
After donating the final part of the fossil in, its plaque in the museum will read:

"The parasaur is well known for the distinctive head crest extending from its nose to behind its head. The crest was formed from a hollow bone that was more than a yard in length. Theories hold that it was used to amplify the creature's vocalizations for a variety of reasons."

The Parasaurus can be found in the first room of the fossil exhibit in the museum.

Real-world information
Parasaurolophus was an herbivorous ornithopod dinosaur. It lived 76 to 73 million years ago in North America and possibly Asia. While no complete skeletons have been found, it is estimated to reach about 9.5 meters long and weigh 2.5 metric tonnes. It is best known for its crest, which evolved from the premaxilla and nasal bones and contained a hollow tube extending from the nostrils before turning around and heading back into the skull. Hypotheses for the purpose of the crest include sexual display, communication, and thermoregulation.