In an exciting revelation that could rewrite the evolutionary history of tyrannosaurs, scientists have identified a new species of dinosaur from a collection housed in a Mongolian museum. This significant discovery, documented in the prestigious journal Nature, indicates that the two 86 million-year-old skeletons studied belong to a species that is now recognized as the closest known ancestor of all tyrannosaurs, the infamous group of predatory dinosaurs that includes the legendary Tyrannosaurus rex.
The newly named species, Khankhuuluu mongoliensis (pronounced khan-KOO-loo), translates to "Dragon Prince of Mongolia." According to Prof. Darla Zelenitsky, a palaeontologist from the University of Calgary in Canada, the term "prince" signifies that this dinosaur is an early, smaller member of the tyrannosauroid family. Tyrannosauroids are a superfamily of carnivorous dinosaurs characterized by their bipedal locomotion.
PhD student Jared Voris, who led the research alongside Prof. Zelenitsky, elaborated on the evolutionary significance of Khankhuuluu. He described these ancient predators as "really small, fleet-footed hunters," who lived in the shadows of larger apex predators during the Jurassic period. This discovery marks a crucial evolutionary shift from these diminutive hunters to the colossal tyrannosaurs that would later dominate the dinosaur era.
Weighing approximately 750 kg, Khankhuuluu serves as a transitional fossil between its smaller ancestors and the mighty T.rex, which could weigh up to eight times as much. Prof. Zelenitsky emphasized the importance of this finding in revising the tyrannosaur family tree and enhancing our understanding of how tyrannosaurs evolved into the powerful predators they became.
Additionally, the new species exhibits early evolutionary traits that were instrumental in the success of tyrannosaurs, such as specific skull anatomy that contributed to a robust jaw structure. Voris noted that features found in the nasal bone of Khankhuuluu eventually led to the powerful bite forces characteristic of later tyrannosaurs. This evolutionary advancement allowed T.rex to prey on larger animals and even bite through bone, solidifying its status as a formidable predator.
The two partial skeletons analyzed in this groundbreaking study were first unearthed in Mongolia during the early 1970s and were initially classified as belonging to an existing species known as Alectrosaurus. However, upon further examination, Voris recognized distinctive tyrannosaur-like features that set these fossils apart. Prof. Zelenitsky recalled the moment she received a message from Voris, indicating his belief that they had discovered a new species.
The ability of these dinosaurs to traverse between North America and Asia, utilizing land bridges that once connected Siberia and Alaska, facilitated their adaptation to various ecological niches. Voris explained that this migration played a significant role in the evolutionary development of different tyrannosaur groups over millions of years. Prof. Zelenitsky concluded by stating that this discovery reveals that before tyrannosaurs assumed their roles as apex predators, they were, in fact, "princes" of the dinosaur world.
