Set 65 million years ago, this is the story of Aladar, an iguanodon who is separated from his own kind and raised by a clan of lemurs, including the wisecracking Zini and the compassionate Plio. When a meteor shower destroys their home, Aladar and his family follow a herd of dinosaurs heading for the safety of the "nesting grounds." Along the way, Aladar befriends Baylene, an elderly brachiosaur; Eema, an unstoppable styracosaur; and Neera, a feisty fellow iguanodon. Together, they must stand strong amidst food and water shortages, the threat of carnotaur attacks, and Aladar's run-ins with the herd's stubborn leader, Kron.