Hundreds of millions of years ago, when dinosaurs ruled the earth, a small group of ancient nocturnal reptiles unwittingly found a survival strategy that led to the evolution of the brain
The study suggests that the closest relationship living mammals called megacranial animals, which had larger brains and nasal cavities than early reptiles.
 The development of a sense of smell drove the evolution of ancient reptile brains, scientists have concluded from the fossilized skulls of reptiles that closely resemble primitive mammals