https://www.livescience.com/archaeology/the-oldest-archaeological-sites-in-the-americas
https://www.smithsonianmag.com/history/tracking-humans-first-foootsteps-north-america-180984292/
THANKS MUCHO
First all thanks to those providing additional interesting links.
For those wondering how the linguists found the ancient languages, they did not, nor did the article say that they did. What they did do was analyze current languages or information gathered on recently dead languages, which anthropologists have been doing at least since the 1800s. starting in the 1500s, the Spanish priests were recording languages in Mexico and elsewhere so they could convert the population. Perhaps they recorded some languages of smaller groups that no longer have their language from that period, but now speak one of the dominant languages.
I studied a bit of Aztec language in Mexico over 60 years ago during a linguistics class. If I remember correctly, Nahuatl is one of the languages with the word “I” beginning with the letter “n”, unfortunately I no longer remember the Aztec word for “you”. At that time I was told Nahuatl was spoken by 1/2 million Mexicans. For many it was the only language they spoke. In southern Mexico, a group of us rode horses 6 miles to visit a large village (at least 500 people) near San Cristobal de las Casas, that had no road, only trails. We spoke to the Alcalde (mayor) and his 2 deputies asking permission to visit in and photograph in his village. They were the only people in the village who spoke Spanish. I don’t know what the rest of the villagers were speaking but it was not Spanish or Nahuatl.