As the Winter Solstice Celebration approaches, Mr. Pteranodon, Larry Lambeosaurus, and their new friend Mr. Seastar still can’t seem to find a way home. As Mr. P and Larry continue to argue, Mr. Seastar tries to remind them of the true meaning of the Winter Solstice Holiday – spending time with family and friends.

While still rolling down the river on the Dinosaur Train Riverboat, Grandpa Pteranodon tells Buddy about the Legend of Admiral Globidens – a HUGE Mososaur that supposedly lives on the river, but no one has ever seen. Buddy enlists Dad and Tiny’s help to look for Admiral Globidens, but they can’t seem to find him. Does Admiral Globidens really exist, or is he just a figment of someone’s imagination?

The Pteranodon Family decides to take a little vacation and swap nests with Larry’s friends: a family of pterosaurs (Nemicolopterus, to be exact). But when the Pteranodon Family arrives at the Nemicolopterus nest, they realize that the Nemicolopterus Family is MUCH smaller than them, so everything is smaller: the Pteranodon Family doesn’t even fit in their nest! Can the family make do, try something new, and still have a good time?

Tank Triceratops is really excited to show Buddy, Tiny, Shiny, and Don his favorite picnic spot, but when they arrive, the spot is overrun with a whole herd of Triceratops. Tank and the kids try to find another place with a little more privacy (and a lot less Triceratopses), but no matter where they go, the herd follows them. Will Tank be able to find a quiet spot without the herd, or does the herd have a good reason for following Tank around?

Mom takes Tiny, Buddy, and Don on a super secret daytrip to Qianzhousaurus Pond, where they meet Quentin Qianzhousaurus – a Tyrannosaur with similar features to Buddy, except for one major thing – Quentin has a long, thin snout covered in tiny horns! The kids think that Quentin’s long snout gives him a super smelling sense, but after a series of tests, they realize that he and Buddy have the same sniffing power. Can Quentin and Buddy’s super sniffers solve the mystery of Mom’s secret daytrip?

Mrs. Pteranodon organizes a “Mom’s Campout” with other moms and kids in the neighborhood. While on the way to the campout, Mr. Conductor challenges the kids to make a real “nature connection” by creating games that push them to look at nature from a different point of view.

The Conductor takes the Pteranodon Family for a special trip to Lizard Island, where they discover that it’s been overrun by plants and bugs, and there are few precious lizards left. The Conductor concludes that the Changyuraptor Family (that he dropped off there awhile ago, and has since multiplied) has been eating all the lizards and throwing the entire ecosystem out of balance. Can the Pteranodon Family and Mr. Conductor convince the Changyuraptor Family to leave their home in order to get the island ecosystem back in balance?

With a hurricane looming, the Pteranodon Family convinces the Conductor to leave his train for the night and come with them to the safety of their hurricane shelter (a large, underground cave). But the Conductor has a hard time getting comfortable away from his train. Can the family and the Conductor pull together and help a family of beached Ichthyosaurs back into the ocean after the hurricane leaves them beached on the shore?

The kids are all excited! Why? Because they’re off to Junior Conductor’s Academy in Laramidia, to try to become Junior Conductors First Class. Buddy has a feeling he’s going to be a star in class, until he meets Dennis Deinocheirus – a kid who knows even more dinosaur facts than he does! Can Buddy get over his disappointment that he’s not the smartest kid in class, and make friends with Dennis (who seems like he’s having trouble making friends on his own)?

Now that Buddy and Dennis are friends, they have to work together (with the other kids) in order to pass a series of tests. If they succeed, they’ll receive their Junior Conductors First Class pins! But standing in the way of their success is the most challenging instructor of all… Thurston Troodon!

Crystal and the King organize a benefit concert to prevent over-fishing of the Big Pond.

Crystal gets stage fright when she's getting ready to perform at the concert.

Shiny invites Annie Tyrannosaurus to Pteranodon Terrace for a sleepover, but all Annie wants to do is investigate the “spooky tree” that Don says “comes alive at night.” All Shiny wants to do is stay as far away from the tree as possible. Can the kids get to the bottom of the mysterious tree, and figure out if it really comes alive at night?

When Don stumbles across a stick that looks EXACTLY like Old Spinosaurus, he’s determined to have the grumpy old dinosaur pose for his sculpture (so he can get the Spinosaurus’s features exactly right). But when they arrive at Old Spinosaurus’s home, he makes it clear that there’s no way he’s posing for anything. Can Don convince Old Spinosaurus to pose for his sculpture, or will Don have to come up with another plan?

The Conductor takes the Pteranodon family on a very special journey on a new invention - the Drill Engine Train - in search of the perfect spot for a new Underground Dinosaur Train Station! Don is THRILLED to be venturing into the BIGGEST HOLE THE EARTH HAS EVER KNOWN! Shiny is nervous to be underground, until they meet a new friend (a Mesozoic Mole named NATASHA NECROLESTES), who teaches them all about the different layers of the Earth. Story A Educational Objectives: The Earth has several layers - the crust (a thin, solid outermost layer), the mantle (the deeper, denser layer), and the core (the super dense center that's as hot as the sun). Also, a Necrolestes is a type of Mesozoic mole.

As the Pteranodon Family continues their journey underground, Don accidentally breaks Buddy's trilobite fossil (the oldest fossil in his collection!) When the search for another trilobite fossil turns up empty, their new friend Natasha Necrolestes takes them to Fossil Alley, where the kids learn that the older the fossil, the deeper underground it is. Story B Educational Objectives: You don't usually find fossils from different time periods mixed together in the Earth. The Law of Superposition means that when we see a stack of rock layers, the deeper you go into the Earth, the older the rocks and fossils you find.

The Drill Engine Train burrows into an underground limestone cave, where the Pteranodon Family meets some strange creatures without eyes called "troglobites." In a contest to see who would make the best troglobite, Buddy, Tiny, Shiny, and Don participate in a treasure hunt - with their eyes closed! The kids have to rely on their other senses (with some guidance from the actual troglobites) to navigate the cave and find the prize. Story A Educational Objectives: A speleologist is someone who studies caves. Also, there are creatures called troglobites whose bodies are specially adapted for living in deep caves without any light.

While digging even further underground, the drill bit on the Drill Engine Train breaks. The Pteranodon Family find themselves in the Cave of Giant Crystals, where they learn all about rocks and crystals (what they are, how they're different, how they form). In order to get back home, the Pteranodon Family has to fix the drill bit by finding a mineral harder than the mineral that broke the bit in the first place. Story B Educational Objectives: Minerals form naturally in the Earth and are made of the same thing all the way through, while rocks are made up of a bunch of different kinds of minerals. Minerals come in thousands of different types (more than 4000 to be more exact), many of which form large and beautiful crystals, some of which are harder than others.