Intelligent Life on Earth Before Humans?

I haven't even read this article in full yet but I am posting this link because Elayne sent it to me knowing my interest.

https://www.vice.com/en_us/article/…P3R-d3PJ7n0pKT8

And in reply I told her that that reminded me of one of the first paperback books I bought for myself when i was a child. Anyone else old enough to remember this "International Bestseller?

Referenced in the article: "Prior Indigenous Technical Species"

https://arxiv.org/pdf/1704.07263.pdf