A Mystery about Our Ancestral Genealogy.

There were: 
                1. the Neanderthals in Europe
                2. the Denisovans in Asia
                3. the "hobbit" homo florensiensis in Indonesia

and there was:

                4. homo ????????????????

Here is the source and basis of the mystery re 4:

http://www.bbc.com/earth/story/20150122-is-this-a-new-species-of-human

In one real sense they were our blood cousins.