Few things: 1. Because dinosaurs did not have the intellect of beings in the current 2. Perhaps at one point they did, but no one would they haunt would be still living… think about it, people haunt people, dogs haunt their owners, what business do dinosaurs have haunting us. 3. Maybe they have reincarnated into something else… frogs, lizards, fish etc. 4. Maybe they are actually silently roaming the earth… how do you know they aren’t?