All my life, I've heard that all these gigantic dinosaurs that used to live on Earth had peanut-sized brains. I just accepted this as a fact, and I guess it may be a fact.
But now I wonder: why?! If their bodies were so incredibly huge and everything was so big back then, why did the brains not also follow that rule? How is it possible that such big animals (or elephants/whales today) apparently have such small brains?
Why doesn't the size of the body roughly dictate the dimensions of the brain inside? Or do they mean this in a more metaphorical way, such that "small brain" really means "low-capacity brain" rather than it actually being physically small? I would assume that if a brain is big, it automatically features more "raw power" rather than being full of empty, unused space.