Raptors get all the brain fame, but the real clever girls were Troodons (pronounced with three syllables: true-o-don). Troodons had the largest brain mass compared to body size of any dinosaur, and are widely regarded as the smartest dinosaur ever discovered. As if being the biggest nerds in the dinosaur kingdom wasn't badass enough, these carnivores probably braved cold weather like little troopers, and there's good evidence that the men took care of the eggs while the women hunted. Got to love dinosaur gender equality. Artwork by NTamura.