Which was the smartest dinosaur?

Although there is no direct way to measure a dinosaur's intelligence, one of the few possible measures of intelligence might be a large brain in a small body. The genus that perhaps fits this description best was the Cretaceous bird-like dinosaur Troodon, which also may have had binocular vision (depth perception) and excellent eyesight and was built for speed. Even so, this dinosaur was probably not as “intelligent” as most modern birds and mammals.