Unknown Island (1948 SciFi)

Adventure-seeker Ted Osborne has convinced his finacee Carole to finance his expedition to an uncharted South Pacific island supposedly populated with dinosaurs. Piloting their ship is Captain Tarnowski, a ruthless alcoholic suffering from malaria- induced bouts of insanity. When they arrive at the island, they discover that the stories they have heard are all true. Will they survive to tell anyone what they've found?