There have not been any skeletons of American Indians/Native Americans older than 6,000 years old ever found in the Americas. Skeletons older than 6,000 years are other people more akin to the Kennewick Man variety.
There is one skeleton found named, 'Stick Man,' that does not 'fit' anywhere with known living humans, from James Chatters in his book about Kennewick Man, Ancient Encounters.
Is it by morphology or by DNA ?
There was a skeleton found in Australia, whose DNA had been preserved because of the climate, which also had DNA unrelated to any living humans. I wonder if these two are related, and represent a line that died out.
Again, this might indicate the New World/Australian connection in population type.