Compared with Tyrannosaurus rex specimens, the Dueling tyrannosaur had significantly longer forearms, fewer tail vertebrae, and more teeth.
Sources
- Mini-tyrannosaur lived alongside T. rex, extraordinary fossil confirms (science.org)
- https://www.nationalgeographic.com/science/article/nanotyrannus-t-rex-dueling-dinosaur-fossil-debate (nationalgeographic.com)
- https://www.sciencenews.org/article/nanotyrannus-not-teenaged-t-rex (sciencenews.org)
- https://www.abc.net.au/news/science/2025-10-31/new-research-t-rex-nanotyrannus-debate-duelling-dinosaur/105946658 (abc.net.au)
- https://www.smithsonianmag.com/smart-news/this-tiny-tyrannosaur-could-settle-a-huge-scientific-debate-180987611/ (smithsonianmag.com)