There are many theories that were put forward by the evolutionists which included the spread of a disease like an epidemic, competition with other animals, overpopulation and the mental disorders. Though, mental disorder may seem a bit perplexing as an evidence of any animal getting extinct but the small size of the brain of dinosaurs when compared to their large size can play a role in their extinction from the planet.

A research conducted on the dinosaurs for two hundred years suggested that almost 99% of the dinosaurs have a very small brain. This is evidenced from the skull fossil of dinosaurs from which it can be found out that how much space was there for the brain. Most of the dinosaurs were actually cold blooded just like lizards today and hence the changes in their body system were automatic rather than controlled by the brain. This shows that the dinosaurs did not require decision making ability like mammals and other animals and hence cannot think ahead of time. If this finding about the dinosaurs is true then it is for sure that they were at danger because of the evolving world around them as they would be unable to cope with it. They might not be able to compete with other more efficient forms of life and hence gradually died, ultimately becoming extinct.

The dinosaurs had a brain as small as that of kittens. The brain was very small when compared to their total body size. The capacity of the brain thus was very small and so was their response to the environment around them. Thus, there capacity to think was less they could not compete with other animals that evolved during the cretaceous period. They also had lack of consciousness and their behavior towards changing pattern was slow.