A world famous anthropologist (Claude Rains) leads an expedition to the Amazon where he claims he has discovered a "lost world" where dinosaurs still live. Loosely based on the novel by Sir Arthur Conan Doyle which had been filmed previously in 1925. The previous year Jules Verne's JOURNEY TO THE CENTER OF THE EARTH had been a great success for 20th Century Fox and hoping for a repeat success, this "B" film with an "A" budget was whipped up but it simply lacks the charm and magic of the 1959 Jules Verne film. On its own, it's an undiscriminating and modestly entertaining boys' adventure but ultimately a routine effort. One can't help but wish that Ray Harryhausen had been brought in to do some of that movie sorcery that makes his films so special. But youngsters should find it agreeable. Directed by Irwin Allen (VOYAGE TO THE BOTTOM OF THE SEA). With Michael Rennie, Jill St. John, Fernando Lamas, David Hedison, Richard Haydn and Ray Stricklyn.