Worlds of Ultima: The Savage Empire

The Avatar, the Earth-born hero of the magical realm of Britannia, has discovered a mysterious black moonstone there. He returns to our world and asks his friend, the natural museum curator Dr. Rafkin, to analyze it. A reporter named Jimmy Malone is eager to cover the story and joins the two. However, the experiments triggers a gigantic explosion, and the group is teleported to a seemingly otherwordly place known as the Valley of Eodon, where native tribes with Mesoamerican and African characteristics co-exist with Neanderthals, dinosaurs, as well as sentient reptile and insect species.