They happened upon the best, most complete skeleton of a teenage T. rex that had ever been found. It was the keystone fossil that told paleontologists that the King was a gangly, long-snouted, thin-toothed sprinter as a youngster, before it metamorphosed into a truck-size bone-crunching brute as an adult.
Mike Henderson & Scott Campbell from the Burpee Museum in Rockford, Illinois.
