There was a guy years ago, 1970's or so, that claimed some of the native languages were related to obscure North AFrican Arab dialects, America B.C., I think. I never went into it much. Also claimed some were related to ancient Greek.
The 1970s were home to a lot of new age junk science. Even more obvious when those that actually wrote those books had almost no experience or background in what they were trying to get others to believe.
I do remember that book, it was written by of all things a zoologist that specialized in invertebrates. But he wrote a ton of quackery books after he retired. Including that North America was discovered by the Celts, Phoenicians, Egyptians, and the Basque.
Myself, I place his works right up there in importance with "Chariots of the Gods", "The Protocols of the Elders of Zion", "The Bermuda Triangle", and "The Jupiter Effect".
This is the same era that a famous porn publisher created a magazine dedicated to exploring pseudoscience at the urging of his wife. And even though it was popular among some readers for various things, shortly after she died he shut it down.
And among the most well known at that time was Alan Landsburg. He produced a slew of them, including "The Outer Space Connection", "Secrets of the Bermuda Triangle", and many others trying to prove anything from a link to Oswald and Ruby to many others. But is mostly known for his popular series "In Search Of".
But there is one big problem that tends to shut down any that try to make such claims. The crossing of new species across the oceans. There is one thing in common with all groups that travel distances like that, they tend to either bring their own species with them for food, or bring newly discovered species home with them as curiosities.
When Columbus returned to Spain in 1493, he brought with him parrots, tobacco, a new species of cotton, and pineapple. And when they returned to attempt colonies they brought with them horses, cattle, pigs, cats, and other plants and animals. Yet there is no evidence of any such introductions of plants and animals from the Americas into Eurasia and Africa in those ancient times, and no evidence of of plants and animals from the Americas to those continents.
Which is especially puzzling, as crops like maize and potatoes would have been extremely popular. And we know that such introductions tend to spread like crazy as there are no diseases or animals that are a threat to them. That is why boars are not native to the Americas, but spread like crazy once some got loose. And in much of the US kudzu and Spanish moss are a huge problem.
Fell is not a "run of the mill crank", but he is still a crank. Writing books based on things he has absolutely no business writing in other than as entertainment. I read a lot of them back then, mostly as I found them rather funny.