Overview
- The nearly complete tyrannosaur entombed with a Triceratops was at least 14 years old and near full size, according to bone growth-ring analysis.
- Researchers distinguish Nanotyrannus from T. rex by higher tooth counts, distinct tooth shapes, longer limbs, and relatively larger arms.
- The study assigns specimens to Nanotyrannus lancensis and a newly named species, Nanotyrannus lethaeus, based on skull and skeletal differences.
- The fossil was discovered in Montana in 2006 and became available for research after the North Carolina Museum of Natural Sciences acquired it in 2020.
- Findings suggest many fossils labeled as juvenile T. rex may need reevaluation, though some paleontologists welcome the data with caution and call for more specimens.