With a skull that's barely taller than the diameter of a quarter, the remains are thought to have belonged to a dinosaur that was less than a year old when it died, and researchers think it measured just 3 feet (1 meter) long and weighed only 3 lbs. (1.3 kilogram).
But the baby may have grown into a bruiser in adulthood, possibly comparable to the 16-foot-long (5 meters) Monolophosaurus, a theropod dinosaur with a long bony crest on its head, or the 25-foot-long (7.6 m) Sinraptor, which means "Chinese plunderer." What's more, it was likely a meat-eater that stalked lizards and relatives of today's mammals and crocodilians, researchers say.