When Tom and Jamie enter the Dino World this time, something is different. The mountains are volcanoes and the weather seems strange. They've gone to the Jurassic period, and there's a whole new world to explore.

"Now that Oona's dino-baby has hatched from its egg, things have gotten even wackier! Stacy the enormous stegosaurus, can't wait to explore her new world. And Oona can't wait to show her off. But not everyone's ready for this big bundle of joy whose having the time of her life romping and chomping through West Woggle. With Bonk, Bruce Brute, Erma, and even the mean witch, Old Brouhaha, on the case, this loveable babe finds her right place in the hearts...

"Danny and Lin have gotten pretty good at taking are of tiny dinosaurs so when Lin's mom asks them to babysit Lin's little sister, ChuChu, they're sure they've got it covered. After all, what better place to spend an after noon than hanging out in the Fruity Stars Lab and playing with the Microsaurs? They will be the best babysitters ever! But when the biggest Microsaur they've ever seen starts a stego stampede. Danny and Lin realize they are up for...

"Baby Stegosaurus travels with the herd, munching on plants. When a volcano erupts, the dinosaurs run, but Baby Stegosaurus can't keep up and is swept downriver. It'll take luck (and some help from Mama) to bring the little dino back to the herd"--