Scientists have identified a new species of dinosaur that is now believed to be the closest known ancestor of the famous Tyrannosaurus rex. The species, discovered in a Mongolian museum collection, has been named Khankhuuluu mongoliensis, which translates to Dragon Prince of Mongolia.
Newly Found “Dragon Prince” Dinosaur Changes T.rex Evolution Story
The partial fossils, first found in the 1970s and initially labeled as another species called Alectrosaurus, were re-examined by Canadian PhD student Jared Voris. Upon closer study, Voris noticed unique tyrannosaur-like traits and shared his findings with his mentor, Prof Darla Zelenitsky from the University of Calgary.
“I remember getting a text from him – that he thought this was a new species,” Prof Zelenitsky recalled.
Transitional Fossil with T.rex Features
The fossils, dated to be 86 million years old, show that Khankhuuluu was a mid-sized predator weighing about 750kg. In contrast, the adult T.rex could reach weights eight times greater. This makes Khankhuuluu a transitional species between smaller Jurassic hunters and the massive tyrannosaurs that later ruled North America and Asia.
“‘Prince’ refers to this being an early, smaller tyrannosauroid,” explained Prof Zelenitsky. Tyrannosauroids were two-legged carnivores that evolved into the T.rex and its powerful relatives.
“They were these really small, fleet-footed predators that lived in the shadows of other apex predatory dinosaurs,” added Voris.
Khankhuuluu also shows early signs of the powerful bite T.rex became known for.
“We see features in its nasal bone that eventually gave tyrannosaurs those very powerful bite forces,” Voris said. These traits likely helped later tyrannosaurs hunt larger animals and even crush bone.
The findings, published in Nature, help reshape the tyrannosaur family tree.
“It has helped us revise the tyrannosaur family tree and rewrite what we know about the evolution of tyrannosaurs,” said Zelenitsky.
Interestingly, scientists say ancient land bridges between Alaska and Siberia helped tyrannosaurs migrate and evolve across continents.
“That movement back and forth between the continents basically pushed the evolution of different tyrannosaur groups,” Voris explained.
Prof Zelenitsky summed it up: “This discovery shows us that, before tyrannosaurs became the kings, they were princes.”