Luminesciopteryx

A semi-sentient bird with glowing wings.

Role in the Movie
The luminesciopteryx was found by the characters in the glowing caverns. A large flock of them led them to the underground world, and a particular juvenile befriended Sean and led him across the magnetic canyon, to the Albino Giganotosaurus's hunting ground. He later decided to keep it as a pet, but when they came to the above-world, it's free instinct took over and it flew back to the underground world, ending the movie.