Khankhuuluu mongoliensis is a newly identified dinosaur species from Mongolia, nicknamed the "dragon prince," that lived about 86 million years ago and is considered a crucial "missing link" in the evolution of T. rex. It was a medium-sized, slender predator, about the size of a horse, with features bridging the gap between earlier, smaller tyrannosauroids and the giant apex predators like T. rex. The fossils were discovered in the 1970s but were only recently studied and classified as a new species in 2025.