During an attack on a pack of Iguanodon an egg is separated and ends up with the possession of a group of lemurs. The lemurs care for this egg and the young creature born from it which they call Aladar. When a meteor shower hits earth Aladar and his family must leave their homeland. Away from home and as close to danger as they have ever been they meet up with a huge group of dinosaurs led by Kron and Bruton. All together they are trying to reach the nesting grounds but it''s not going to be easy.