currently reading west of eden by harry harrison. "In the parallel universe of this novel, Earth was not struck by an asteroid 65 million years before the present. Consequently, the Cretaceous–Paleogene extinction event which wiped out the dinosaurs and other reptiles never happened, leaving the way clear for an intelligent species to eventually evolve from mosasaurs, a family of Late Cretaceous marine lizards closely related to the modern monitor lizards. This relationship would mean that the intelligent species are not dinosaurs but lizard-people. The lizard-people are known as the Yilanè, and are the dominant life form on most of the planet. However, during the evolutionary process, the species became non-viable on the two American continents, leaving them free of Yilanè for millions of years and opening an ecological niche for a top predator. A human-like species, the Tanu, evolved to fill the niche in North America, but are only found on that continent. Unlike humans, which evolved from African primates, the Tanu have evolved from a lineage of New World monkey. By the time the novel begins, the humanoids have reached a late stone age level of technology and culture, with a number of societies having developed farming skills". [wiki] 35 pages into it on my tablet and really enjoying it. driving toyorkshire today to tour the charity shops for books, still read the paper if the price is right.