A wealthy, egotistical big-game hunter and industrialist funds an expedition using an experimental drilling vehicle to reach a hidden tropical world beneath the polar ice cap, where dinosaurs still roam and a primitive tribe survives. He becomes obsessed with killing a massive Tyrannosaurus that has eluded him, even as the expedition's survival hangs in the balance. Rankin/Bass and Tsuburaya (of Godzilla fame) co-production starring Richard Boone.