Answer:
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.

Ceratosaurus
nasicornis, from Marsh (1896)
Orginal specimen on display at U.S. National Museum