That is a most ridiculous statement on so many levels.
Dinosaurs lived for 165 million years and alongside mammals for 160 million years. Mammals were only rat sized. What chance would you give if you were an outside observer, say 155 million years ago, that after so many years living side by side and dinosaurs dominating, that mammals would eventually take over, much less that an intelligent animal like humans would evolve? You'd be skeptical.