I'm looking for a novel about intelligent dinosaurs and aliens.
Probably published in the early 90's. Paperback, English.
Cover was a green alien resembling a small, predatory dinosaur (similar to Dale Russell's "dinosauroid"), facing out and aiming a sci-fi weapon. The background was a reddish orange desert, possibly with a spaceship.
Plot: The story takes place in a theocratic near-future America. Paleontologists dig up a mysterious box that turns out to contain several living dinosaur eggs which proceed to hatch into blue and yellow feathered Deinonychus (raptor) dinosaurs. The dinos are extremely intelligent and grow unnaturally fast.
An alien spaceship appears and the alien asks for possession of the eggs. People freak out. The main character paleontologist is invited inside the ship, where the dinosaur like alien gives him a tour of its zoo of living dinosaurs. It explains that it is not actually related to Earth dinos, but visited the planet just before the great extinction and tried to preserve some. The newly hatched dinos were part of a failed experiment to uplift the species into full intelligence, but the forced rapid growth means they matured too quickly to learn a moral system and as a result are extremely vicious. The alien is a pacifist and wants permission from Earth to take them, despite being advanced enough to just swoop in and do whatever it wants.
Of course there are complications with the religious people, and one of the dinos, nicknamed Jekyll for it's rapid swings between child-like curiosity and animalistic aggression, has escaped and is causing havoc.
Eventually everything ends badly, with the young dinosaurs killed and the disappointed alien leaving.