The Pteranodon kids are riding the Dinosaur Train with friend and fellow pterosaur, Quincy Queztalcoatlus. When they pass by a waterfall, Buddy comments on how big it is! Quincy's dad mentions a giant waterfall at the edge of the Western Interior Sea. Mr. Conductor gives a lesson about waterfalls and then suggests a unique and amazing way to view the giant falls - from above! They can fly in the experimental Dinosaur Train Zeppelin...if Thurston Troodon will agree to take them all there on the Zeppelin's maiden voyage. Thurston does and our Pteranodon family gets to experience a spectacular Zeppelin ride! The Queztalcoatluses fly alongside, impressing everyone with their flying abilities. After learning more about waterfalls, the Pteranodons catch lots of fish and dine before heading back to the Train via the one-of-a-kind Dinosaur Train Zeppelin! When the Pteranodon family spots Annie and her T. Rex herd migrating to follow the food, the Pteranodon kids wonder if other creatures, even marine mammals, also migrate. The Conductor flies the Pteranodon family over the ocean in the Dinosaur Train Zeppelin to look for Polycotylus, a type of marine reptile that does migrate in the ocean. After spotting a pod of migrating Polycotylus from the sky, the Zeppelin lands in an atoll and our family meets Paulette and Polly Polycotylus, a mother and daughter from what is modern-day Australia. Our Pteranodon kids, Mom, Dad and the Conductor learn all about Polycotylus migration and the reptile features. Then the whole group of new friends enjoys a fishpicnic on the reef of the atoll before the Pteranodon clan heads back home in the Zeppelin.