While Mikey Microraptor is visiting Tiny at the family nest, next-door neighbor Larry Lambeosaurus tells Mikey that he can't actually be a dinosaur, since he's so small, and all dinosaurs are gigantic. Tiny and Mikey decide to show Larry he's mistaken. They take the Dinosaur Train to find the tiniest dinosaur of all - in Jurassic China. There, they meet Yi qi, a new tiny dinosaur, the size of a pigeon, whose name means "strange wing" because its wings are made of skin! She's otherwise covered in feathers. Tiny and Mikey learn Yi qi's point of view: "Everyone thinks dinosaurs are huge. I'm small, but I'm still a dinosaur!" Mikey is thrilled to meet a dino smaller than himself. Then Mikey, Tiny, and Yi qi bond over being small but proud, and exclaim their rallying cry of "Tiny Power!" Yi qi joins this group of tiny dinosaurs. The Conductor is inspired to create a Tiny Dinosaur Train, especially adapted to accommodate tiny dinosaurs. Larry meets the tiniest dinosaur when the Tiny Dinosaur Train rolls into the station, is properly impressed, and the kids sing a new "Tiny Power!" song / Buddy and Tank Triceratops are best friends, and they share a love for comparing features. Tank, who has 3 horns, wonders why Mayor Kosmoceratops has 15, and Protoceratops has only 1. Buddy, Tank, and the other kids go on a quest to track down Ceratopsians with horns numbering from 1 to 15. In their travels, they end up meeting "the Queen," an amazing Late Cretaceous Regaliceratops, who has a very decorative frill that almost rivals Kosmoceratops for number of horns!

The kids happen upon the legendary giant bullfrog, Benny Beelzebufo, who they once visited on his home river. Benny got off the Train at the wrong stop and is in new territory - the Pteranodon Family neighborhood. The kids take him around and show him fun places and play games with him. Then, he gets worried - he has to be home for dinner! A problem with the Dinosaur Train means our Pteranodon kids and Dad - with the help of good friend, Pauline Paleobatrachus, a tiny frog - take Benny on a trek over land and on water, and get him home to his family. Benny is thankful and loved his unexpected adventure with the Pteranodons. / When the kids all went to Junior Conductor's Academy, they met Dennis Deinocheirus, a brilliant and autistic theropod who was the first dinosaur kid who knew more dino facts than Buddy! Now, Dennis fulfills a promise and has come to visit Buddy and the kids at Pteranodon Terrace. Buddy, Tiny, Shiny, and Don play host to Dennis and are very sensitive to his needs, manner, and being out of his comfort zone. Dennis ends up having fun playing new games with the kids, digging holes, and playing on the pretend "Dinosaur Train" rocks.

Armored Like an Ankylosaurus - The kids travel on the Dinosaur Train with Mr. Pteranodon to see his hero, Hank Ankylosaurus, play a game of Dinoball. Afterwards, they even get to play with Hank and learn what it's like to be a dinosaur that's covered with armored plates and a mighty club for a tail.Campout! - Our Pteranodon family goes to the Big Pond for their first overnight camp out and meets a small frog with a big voice.

After Shiny and Annie have a disagreement while exploring a local cave, Mom recalls a similar disagreement with her best friend when she was a kid, Tilly Pteranodon. Tilly happens to be visiting that day and the kids get to meet her for the first time. Mom and Tilly have a great reunion, yet they have very different memories of what their childhood disagreement was about-except that it was about an adventure in a swamp and a swamp-dwelling creature. To clear things up, Mom, Tilly, Tiny, Shiny, and Annie go back to Mom and Tilly's old neighborhood and the swamp. / Mom and Tilly (along with Tiny, Shiny, and Annie) return to their old neighborhood to explore the swamp where they used to play as kids and had a disagreement. The disagreement was about a swamp creature - was it a friend or foe? Mom and Tilly discover the creature, who is still there, is a friend! She is GOLDIE the GLOBIDENS, a marine creature who eats mostly shellfish. Mom recalls that she was scared of Goldie as a kid. and that that was the crux of her disagreement with Tilly. But, that was then, and now their friendship is patched up and strong again - a good example for Shiny and Annie.