previously unknown human group

Ancient Siberia was home to previously unknown humans, say scientists.... 
The results reveal these individuals were part of a previously unknown yet widespread group, dubbed the Ancient North Siberians by the team, who were genetically distinct from both Western Eurasians and East Asians...But, crucially, this population does not appear to be the direct ancestor of Native Americans.

Not quite sure who's on first here, but it sounds interesting.