Overview

• Khankhuuluu mongoliensis lived about 86 million years ago, measured roughly 4 meters long and weighed around 750 kilograms as a fleet-footed predator.
• Researchers Jared Voris and Darla Zelenitsky reexamined fossils misidentified as Alectrosaurus at the Mongolian Academy of Sciences, leading to the species’ formal naming.
• Anatomical features such as a slender skull, hollow nasal bones and long limbs show Khankhuuluu lacked the bone-crushing bite force of later tyrannosaur giants.
• Phylogenetic analysis indicates this species or a close relative migrated from Asia to North America around 85 million years ago, seeding the evolution of larger tyrannosaur clades.
• The discovery fills a 20-million-year gap in tyrannosaur evolution and underscores how revisiting museum collections can rewrite established family histories.