Genson! Kodai Seibutsu-shi Packy

Elementary student Takeru befriends a Pachycephalosaurus named Packy, who hails from "The Lost World," a habitat for extinct animals. Packy enjoys head-butting and is on a quest to find the ideal object for this activity. He begins living with Takeru, his older sister, and their parents in their contemporary home. However, Packy is not the only creature from The Lost World to appear, as other beings may pose a threat to the modern world and its people.