Caprona

After a German U-Boat sinks their ship, several survivors manage to take control of the boat. Bowen Tyler is the son of an American shipbuilder and Captain Bradley an experienced seaman. After several tussles with the German crew, they find themselves on a strange island. There they find a place where several stages of Earth's evolution co-exist at the same time. As a result several types of humans are found as well as prehistoric dinosaurs. There are also active volcanoes which all add up to a challenge to survive.

A sequel to The Land That Time Forgot. Major Ben McBride organises a mission to the Antarctic wastes to search for his friend (Doug McClure) who has been missing in the region for several years. McBride's party find themselves in a world populated by primitive warriors and terrifying prehistoric creatures, all of whom they must evade in order to get back safely to their ship.