For years, scientists believed Tyrannosaurus rex reached its adult size at around age 25. But a major new study suggests the iconic predator may have taken much longer to mature. According to the research, T. rex likely continued growing for about 40 years before reaching its maximum size of roughly eight tons.
The findings come from an analysis of 17 tyrannosaur fossils spanning a wide range of ages, from young juveniles to massive adults. Researchers say the work provides the most detailed reconstruction yet of how Tyrannosaurus grew throughout its life.
The study was published in the journal PeerJ.
Reading the Growth Rings Hidden Inside Dinosaur Bones
To estimate the age of dinosaurs, paleontologists often examine growth rings preserved inside fossilized bones. These rings are somewhat similar to the annual rings found in tree trunks. Each growth mark can provide clues about how quickly an animal was growing and how old it was when it died.
