It's time for the "Classic in the Jurassic" - the Mesozoic Olympics! Today's "Air, Water and Land" contest is a three-part competition pitting teams consisting of a pterosaur and a crocodile from each Time Period against one another. Mrs. Pteranodon, Tiny and Shiny are recruited to help in one of the three "legs" of the race, while Buddy, Don and Dad watch from the stands. The competition's three "legs" are flying, swimming and a lap around a track. Early on, Team Cretaceous pulls ahead and hold onto its lead, until the wild card of the race is revealed: Team Triassic's croc, Effie Effegia, who shocks the crowd when she runs, and then sprints, on two legs! Effie wins the race, and her bi-pedal ability prompts many questions - and a healthy discussion -- about her features. Tiny is disappointed her team lost, but cheers up when reminded that she was part of `"Classic in the Jurassic" history. While playing "Cold and Hot," a game they made up, the Pteranodon kids learn from Mr. Pteranodon that there might be more variety in the desert than they imagined. Their curiosity piqued, they plead for a trip to investigate the desert scene. Mr. Conductor tells them just how diverse plant and animal life can be in the desert. He happens to know a desert mammal: Fruitafossor. Upon disembarking from the Dinosaur Train, the Pteranodon kids meet Frankie Fruitafossor, a chipmunk-sized mammal. They quickly learn that their assumption that desert life was hot all the time and relatively uninhabited was incorrect. Come dusk, they find the desert hopping and crawling with life, as creatures emerge all over - mostly underground - where they hide from the blazing sun. Frankie gives our family a tour, including a peek at underground burrows he dug. Back on the desert floor, Don and the siblings can't believe how cold the desert has become. Nighttime in the desert is a different world than daytime! The family goes back to the Dinosaur Train to warm up and have a snack.