Fossil Hunter: Book Two of The Quintaglio Ascension

Fossil Hunter is hard SF in the tradition of Larry Niven about a world inhabited by the Quintaglios, a dinosaurian species that has evolved a human level of intelligence and culture.

Toroca, a Quintaglio geologist, is under attack for his controversial new theory of evolution. But the origins of his people turn out to be more complex than even he imagined, for he soon discovers the wreckage of an ancient starship -- a relic of the aliens who transplanted Earth's dinosaurs to this solar system. Now, Toroca must convince Emperor Dybo that evolution is true; otherwise, the territorial violence the Quintaglios inherited from their tyrannosaur ancestors will destroy the last survivors of Earth's prehistoric past.