Overview
- Two peer-reviewed studies released five weeks apart independently conclude the small tyrannosaur was not a juvenile T. rex.
- The new Science paper analyzed the holotype’s hyoid, showing maturity and establishing that the specimen defines a distinct species.
- Validation tests found hyoid age signals in birds, crocodilians and multiple dinosaurs matched maturity estimates from limb bone histology.
- The earlier October study documented consistent anatomical differences, including higher tooth count, a preorbital crest, an air sinus and a vestigial third finger.
- Findings suggest late Cretaceous ecosystems hosted both T. rex and a smaller, faster predator about 5 meters long and ~700 kg, implying competition with juvenile T. rex and a reassessment of predator roles.