Plot Summary: A female maiasaura finds a lost egg and decides to raise it along her own baby. To the herd's surprise, the child born from the stray egg is a tyrannosaurus. Determined to not leave the newborn behind, the mother abandons the pack and raises her two kids by herself. Named Heart by his adoptive mother, the tyrannosaurus grows up besides his maiasaura brother, Light. Soon enough the siblings discover why Heart is unlike the others and the difference between carnivores and herbivores....