These dinosaur bones have stumped scientists since the 1940s. New evidence claims to solve the mystery

Scientists have long puzzled over the origins of a mysterious dinosaur excavated in the 1940s: Was it a young T. rex or another type of dinosaur?

At first, researchers had only a tyrannosaur skull to go by, making it hard to tell if it belonged to a child or adult. Another skull and skeleton nicknamed Jane added to the debate, but didn’t settle the controversy.

Now a research team said there’s new evidence that resolves the case. The latest clue comes from a complete skeleton — first uncovered in 2006 in Montana — that scientists say identifies the mystery reptile as its own species and not a juvenile Tyrannosaurus rex.

The discovery “rewrites decades of research on Earth’s most famous predator,” said study co-author Lindsay Zanno with the North Carolina Museum of Natural Sc