A paleontologist named Zack takes his nephew Ricky and niece Jade on a fossil hunt. While alone, Ricky is met by a talking rook, who turns into an Alexornis named Alex. He tells him of a story set in the Cretaceous period 70 million years ago. Patchi is the smallest in a litter of Pachyrhinosaurus hatch-lings, and is often bullied by his older brother Scowler. Their father Bulldust is the leader of a Pachyrhinosaurus herd. Alex, who is Patchi's mentor, tries to help Patchi impress a female Pachyrhinosaurus named Juniper, but her herd migrates south without him..