The definitive evidence Nanotyrannus is a unique species came from a DNA study published last month. Once discovered, it was for years misidentified as a juvenile Tyranosaurus rex. Comparative anatomy studies of the rare “Dueling Dinosaurs” fossil led researchers to a groundbreaking revelation. This one finding has completely turned the story related to these famous dinosaurs upside down. The research, which was published in the journal Nature, used cutting-edge methodologies to reconstruct this exceptional specimen.
Researchers had previously utilized Nanotyrannus fossils to model the growth and behavior of T. rex for years, often overlooking its unique characteristics. For decades, the timid species lived in plain sight under the radar of their flashier cousin. The Dueling Dinosaurs specimen seems to have put that debate too close to bed. This amazing specimen beautifully illustrates a fight between a Triceratops and a small-bodied tyrannosaur species named Nanotyrannus lancensis.
The Dueling Dinosaurs fossil revealed an incredible surprise. The specimen was roughly 20 years old and had attained full physical maturity at the time of death. This rocks the boat of a long-held assumption that Nanotyrannus was a juvenile T. rex. Lindsay Zanno, an associate research professor at North Carolina State University, called the find a game changer. She happens to be a co-author of that study.
“This fossil doesn’t just settle the debate. It flips decades of T. rex research on its head.” – Lindsay Zanno
To establish Nanotyrannus as a distinct species, researchers conducted an in-depth examination of growth rings, spinal fusion data, and developmental anatomy across more than 200 tyrannosaur fossils. To their surprise, they found a skeleton once thought to belong to a teenage T. rex. It differed strongly from Nanotyrannus lancensis.
James Napoli, an author on the research team, articulated what’s at stake with their conclusions.
“For Nanotyrannus to be a juvenile T. rex, it would need to defy everything we know about vertebrate growth.” – James Napoli
The research indicates that multiple tyrannosaur species, including both T. rex and Nanotyrannus, coexisted within the same ecosystems during the final million years leading up to the catastrophic asteroid impact. This important find creates a fuller, more dynamic and highly competitive portrait of the final days of the dinosaurs.
“This discovery paints a richer, more competitive picture of the last days of the dinosaurs.” – Lindsay Zanno