While riding the Dinosaur Train with Buddy and Mom, Tiny gets the idea to gather all the dinosaurs in the `Dinosaurs A to Z' song for a picnic at Troodon Town. The Conductor agrees, and the Train starts picking up dinosaurs, as Tiny and Buddy help keep track of how many of the different species have come on board, and where they are on the dinosaur A to Z list. The Dinosaur Train continues traveling around the Mesozoic picking up more and more dinosaurs that are in the `Dinosaurs A to Z' song, on the way to a picnic at Troodon Town. As more train cars are added, and the rest of the Pteranodon family comes on board, Tiny and Mrs. Conductor team up to help keep order on the increasingly crowded Train.