Aladar's mother was an Iguanodon taking care of her nest that was filled with eggs, scaring off a baby Parasaurolophus at one point when it sniffed one of her eggs. Suddenly, a Carnotaur appeared from the woods and started chasing all of the dinosaurs present in the Nesting Grounds. The Iguanodon tried to resist as much as she could with her nest, but the Carnotaur was coming so fast that she was forced to flee with the others. In the ensuing chaos, one dinosaur was killed and many eggs were destroyed. Only one of the eggs survived the attack; this egg was taken by an Oviraptor, but it ultimately dropped it into a river as it was fighting against another Oviraptor for claim of the egg. The egg was eventually picked up by a Pteranodon as it flew far away to an island and ended up dropping the egg. The baby hatched here and was raised by a lemur family consisting of Plio, Yar, Suri and Zini. Plio is the one who named the baby Aladar.
It is unknown whether or not she was alive by the time Aladar arrived at the herd.