Did dinosaurs have more than one brain? If so, why?
It would appear that at one time it was thought that a &quot;gap&quot; in the skeleton of a Stegosaurus was a space for another brain. This is now thought to be a storage space for extra food.
Googling your question brings up a number of answers along these lines:

https://en.wikipedia.org/wiki/Stegosaurus#%22Second_brain%22
https://dinosaurs.about.com/od/dinosaurdiscovery/tp/dinoblunders.htm
https://wiki.answers.com/Q/Did_a_dinosaur_have_two_brains