Harry Harrison-Eden. The trilogy. Gift book bound in leather.

An asteroid that collided with Earth 65 million years ago, causing a massive and rapid extinction of the giant reptiles that dominate the planet, according to Harry Harrison, passed by.... And the dinosaurs did not die out, but continued to evolve and having gained intelligence, they created their own, completely different from the modern civilization.

Other species also evolved along their own paths. The primates also gained intelligence and entered into a struggle for survival. With the help of fire and manufactured tools, the first people enter into a seemingly hopeless battle for life with intelligent reptiles...

Will people be able to make up for the huge time handicap given to dinosaurs by nature and survive?