Tyrannosaurus rex may have been the largest land predator ever to walk the Earth, but it did not grow into that role quickly. A new study suggests the famous dinosaur took around 40 years to reach its full adult size, significantly longer than scientists had previously believed.
Researchers examined microscopic growth patterns inside the leg bones of 17 T. rex fossils. Much like tree rings, these bones preserve annual growth marks. Using polarized light, the team identified previously unseen rings that revealed a slower and more flexible growth process.
The findings suggest T. rex spent much of its life as a juvenile or subadult, growing quickly in some years and barely at all in others. Scientists believe this stop and start pattern likely reflected changes in food availability and environmental conditions, allowing the animal to conserve energy during harder times.
The study also raises estimates of the dinosaur's lifespan, suggesting some individuals may have lived up to 45 or even 50 years. Researchers say the longer growth period may have helped younger T. rexes survive by hunting different prey than fully grown adults, reducing competition until they reached their massive final form...
For more, the study was just published in the journal PeerJ.