In the humid swamps of Late Cretaceous North America, dawn stirs the mist. Ripples spread across still water as a herd moves through the reeds. From within comes a deep, resonant call — clear and melodic, echoing between the trees. This is Corythosaurus — the “helmet lizard.” With its tall, crest-like crown, it fills the air with haunting, musical notes that travel across the wetland. A sound of communication… and companionship.