T. rex took 40 years to reach full size, study finds

Tyrannosaurus rex may have taken far longer to grow up than scientists once thought. By analyzing growth rings in fossilized leg bones from 17 tyrannosaur specimens and using new statistical methods, researchers found that the famous predator likely took about 40 years to reach its full size—around eight tons—rather than the previously estimated 25 years.

source https://www.sciencedaily.com/releases/2026/03/260304184226.htm