The peaceful routine of the Great Valley is abruptly shattered when a voracious swarm of leaf-swallowers—giant, grasshopper-like insects—descends upon the land, devouring every scrap of vegetation in sight. Fearing imminent starvation, the massive herds of long-necks, three-horns, and other dinosaurs are forced to evacuate their beloved home and journey in search of a temporary sanctuary. During the arduous trek, tensions flare between the adults as scarce resources strain their cooperative spirit. Amidst this high-stress environment, the young and adventurous dinosaurs—Littlefoot, Cera, Ducky, Petrie, Spike, and the newly hatched Chomper—struggle to understand the gravity of the adults' disputes. Chomper, a young sharptooth raised by the herbivores, faces growing prejudice and suspicion from older dinosaurs who fear his predatory instincts, though his loyal friends fiercely defend him.Seeking a quicker escape from the barren landscape, the group of adventurous youngsters accidentally becomes separated from the main herd during a chaotic stampede. Their journey leads them to the edge of a vast, turbulent body of water. Desperate and stranded, they construct a makeshift raft out of logs and drift out to sea, enduring treacherous waves before washing ashore on a lush, seemingly idyllic, yet isolated tropical landmass. Believing they have found a paradise untouched by the famine, the friends rejoice, reveling in the abundant food and safe environment. However, their joy is cut short when they realize they are not alone on the mysterious island.Danger quickly manifests when they discover the island is heavily populated by numerous sharpteeth—fierce predatory dinosaurs that view the youngsters as easy prey. Panic sets in, but their survival instincts kick into high gear as they must navigate the perilous terrain. Matters take a deeply emotional turn when Chomper unexpectedly reunites with his
biological parents, a pair of adult sharpteeth. Despite their initial terror, the young herbivores are stunned when Chomper’s parents do not attack them, thanks to Chomper’s influence and his parents' strange, begrudging tolerance of his herbivore friends. This fragile peace is shattered when a massive earthquake and volcanic eruption strike the island, causing widespread chaos, molten lava flows, and collapsing terrain.Working together, the herbivores and Chomper’s family must put aside their natural predatory instincts and prey-predator dynamics to survive the fiery cataclysm. In a tense climax, Chomper bravely helps orchestrate a daring escape, using the island’s aquatic exit to guide his friends back to the safety of the open water. Shortly after escaping the destruction, the youngsters are finally reunited with their families, who have found a new, thriving valley of their own. The harrowing adventure ultimately fosters a newfound sense of
understanding and mutual respect among the adult dinosaurs, who learn that even the most feared predators can possess compassion, forever changing the social landscape of their prehistoric world.