I keep seeing people say stego has a brain the size of a walnut compared to it's body size, so it must be dumb. But I'm not too sure about that, I know stego doesn't have a second brain, instead having a cluster of nerves that help with locomotion and defense while the brain deals with the rest of the body.
It lived in herds or large family groups, meaning it probably defended it's young from danger. So after all we know now, can it really be dumb, or are we just underrating it's intelligence?