This handout artist's illustration made available by University of Calgary on June 6, 2025, shows the newly discovered dinosaur species Khankhuuluu mongoliensis, an ancestor of Tyrannosaurus Rex. Misidentified bones that languished in the drawers of a Mongolian institute for 50 years belong to a new species of tyrannosaur that rewrites the family history of the mighty T-Rex, scientists said on June 11, 2025. (Photo by Julius CSOTONYI / University of Calgary / AFP)