Researchers have found evidence of interbreeding between the ancestors of neanderthals and denisovans and a previously unknown "superarchaic" hominin. Some reports suggest there may have been interbreeding with two separate "superarchaic" species, although the details are not clear. The discovery sheds new light on the history of human interbreeding, with some findings indicating that this interbreeding may have occurred as far back as 300,000 years ago.