Troödon formosus was a relatively small, bird-like dinosaur from the late Cretaceous Period (68-65MYA). Discovered in 1855, it was among the first dinosaurs found in North America, and is believed to have been one of the most intelligent.
Diet consisted of smaller animals, including mammals
Had one of the largest known brains of any dinosaur relative to its body mass (comparable to modern birds)
Eyes were large (suggesting nocturnal activity) and slightly forward facing, giving T. formosus some depth perception
T. formosus' long arms folded back like a birds', and its hands possessed partially opposable thumbs
Had large, sickle-shaped claws on its second toes which were raised off the ground when running. This claw is common in the superfamily Tyrannosauridae, to which T. formosus belongs
