The Land Before Time begins with the tragic event of the main character, Littlefoot, losing his mother after she protects him from a fearsome predator, leaving him orphaned and tasked with finding the legendary Great Valley.
Based on the provided information, the core event that initiates the central conflict and journey for the protagonist, Littlefoot, is:
The Orphaned Apatosaurus
- Littlefoot's Background: He is introduced as a young dinosaur who is a plant-eater (an Apatosaurus, though the reference only states "plant-eating dinosaur").
- A Vicious Attack: A dangerous carnivore attacks. While the reference doesn't name the carnivore (it is later known as Sharptooth), it emphasizes its vicious nature.
- Mother's Sacrifice: Littlefoot's mother bravely defends him from this predator.
- Tragic Loss: In the process of protecting Littlefoot, his mother perishes. This leaves Littlefoot alone.
- The Dying Wish: With her final breaths, Littlefoot's mother provides him with crucial information: the location and path to the legendary Great Valley. This valley is described as a safe haven where he can reunite with others of his kind.
This pivotal event of becoming orphaned and receiving the quest to find the Great Valley sets the stage for Littlefoot's epic journey and the adventures that follow as he seeks this new home. It's the inciting incident that drives the entire narrative.