Dinosaur eggs preserved by alien hatch, alien comes back for them?

Question

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.

Answer 1

Lords of Creation by Tim Sullivan.

In the deep Montana shale, paleontologist David Albee makes a remarkable discovery: a metal box containing prehistoric dinosaur eggs — warm, alive… and ready to hatch.

One week later, they are among us – newborn creatures from an age long dead. With uncanny intelligence, they adapt to their new world – driven by some strange, unknown purpose. Curious and hungry, they begin to feed… and grow.

But even as Albee struggles to protect his find from the wrath of government agents and religious fundamentalists, gargantuan invaders from a distant star prepare to make contact – armed with earth-shattering revelations that will destroy humankind’s every notion of nature and science… and God.

I wish I could claim this was down to my encyclopaedic knowledge of SF, but in fact I just Googled dinosaur eggs live science fiction site:goodreads.com/book/show/ and there it was.