Cerebrus Rex

From publisher blurb: Cerebrus Rex: On the primordial Earth where this Saurian genius was born, giant reptiles became tool users and conquered and enslaved their Simian rivals. They also developed powerful weaponry capable of ravaging their planet, and used it to do so. Cerebrus Rex sees our Earth as a place to secure the future for his Saurian race. Something might have to be done about all those "primitive Simians" first, however.