A mysterious "runner" dinosaur, only about the size of a dog, scurried around the ancient floodplains of what is now Colorado around 150 million years ago, a new study finds.
The two-legged herbivore, named Enigmacursor mollyborthwickae, was around 3 feet (1 meter) long and 1.5 feet (0.5 m) tall. However, despite its small stature, the discovery of this dinosaur is having a big impact on scientists' understanding of several Jurassic species.
