New Tyrannosaur Ancestor Revealed in Mongolia

Khankhuuluu mongoliensis, a new dinosaur species identified from partial skeletons unearthed in Mongolia in the 1970s and recently re-examined, is now considered the closest-known ancestor to Tyrannosaurus rex. The 'Dragon Prince of Mongolia' lived about 86 million years ago, was horse-sized, and displayed unique features such as a hollow nasal bone that bridge the evolutionary gap between smaller predators and giant tyrannosaurs. The find clarifies how tyrannosaurs evolved stronger jaws and became apex predators, marking Khankhuuluu as a key transitional species. The discovery also disproves past theories that small, long-nosed tyrannosaurs like Alioramus led directly to T. rex. Researchers note the significance of museum collections and international collaboration, suggesting more important specimens may await recognition. The research, published in Nature, enhances understanding of the migration and diversification of tyrannosaurs across Asia and North America.