Fossils have shown that two types of ancient human ancestors coexisted over 2 million years ago. The discovery sheds light on how these human ancestors lived in the same area, with some findings suggesting they may have had adaptations for both walking on two legs and climbing trees. However, the specifics of the discovery, including the identities of the ancestors and the time period, are not entirely clear, with some reports mentioning different time frames and ancestors, including a possible connection to Neanderthals and Homo sapiens.