Punon, a young pteranodon orphaned shortly after hatching, survives a perilous prehistoric world forged by solitude. Flightless yet undeterred, she faces constant threats from predators like Gorgo’s gorgosaurus pack with relentless optimism and curiosity. Her fortunes shift when Tyrano, a carnivore subsisting on red berries instead of prey, rescues her from an attack. Intrigued by his defiance of instinctual norms, she clings to him with talkative persistence, sparking an alliance to seek "Heaven," a fabled sanctuary.

Guiding Tyrano and Tops—a lost triceratops—through environmental hazards and relentless pursuers, Punon bridges their differences, forging a familial bond through shared vulnerability and resolve. Her tenacious spirit anchors the group, turning her quest for safety into a collective mission. Though her origins remain shrouded, her journey transforms her from a solitary survivor into a determined leader, framing "Heaven" as both a destination and a symbol of her unyielding hope for belonging. The narrative confines her story to a single film, focusing on her resilience against physical limits and external dangers.