T. Rex Dinosaur bone study shows it never stopped growing
New clues hidden inside T. rex Bones reveal carnivorans lived longer than we thought
Artist’s rendition A Tyrannosaurus Rex.
Roger Harris/SPL/Getty Images
Dinosaur bones are like trees – each year is represented by a new ring, and paleontologists can count those concentric circles to determine the age of the fossil. But new research shows that in the case of Tyrannosaurus Rex, Some growth rings have still remained unrecognized. That means the king of the tyrannical lizards lived longer than experts expected — and he never stopped getting bigger.
previous estimates T. rexThe lifespan is around 30 years, and the dinosaurs are thought to have reached their full size around the age of 20 to 25 years. New research, published today Peerje, Rewrites that life cycle: Bones from 17 specimens indicate that these hulking predators actually stopped growing between the ages of 35 and 40 and typically reached at least 8.8 tons.
“It took a very long time for the prince to become a king,” says paleontologist Steve Brusatte of the University of Edinburgh, who was not involved in the new study.
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clues are hidden T. rex Leg bones in their entirety: While some growth rings can be seen with visible light, others, it turns out, are visible only in cross-polarized light. Previous research had ignored these weak rings. Holly Woodward, a paleontologist at Oklahoma State University and lead author of the new study, did much the same.
“I ignored it at first, until I started looking at all these samples and started seeing it in many of them,” she says.
It’s not clear what the more subtle rings are meant for – maybe a tap on development would trigger a pause rather than a complete stop. But the team’s analysis shows they paint a complete picture of T. RexReal age of.
Counting growth rings is not as easy as counting tree rings. As the bones expand, “the early growth record is destroyed,” says Woodward, so only the record of the animal’s later years is left behind. But he and his team had access to specimens of varying ages, each capturing a fraction of the species’ lifespan, which enabled them to mathematically nest smaller, younger bones within larger, older bones. That analysis yielded a more complete reconstruction of dinosaur evolution.
since The first study is investigating T. Rex Development In 2004, all evidence pointed towards a creature that was approaching adulthood like humans and other modern vertebrates. one more recent study Describes from 2024 “explosive growth during adolescence” In the absence of more data, many paleontologists accepted those findings, but some were not convinced.
“It seemed very early,” says paleontologist Thomas Carr of Carthage College, who was not involved. PeerJ Study. “Extending the lifespan…makes sense for such a large animal.”
Experts say Woodward and his team’s approach could force paleontologists to reevaluate how fast other dinosaurs and extinct animals grew. And there is still more work to be done to understand the life cycle T. rexEspecially because there are so few juveniles in the fossil record.
Still, paleontologist Lindsay Zaino of the North Carolina Museum of Natural Sciences, who was not involved in the new study, calls the findings a milestone for the field. “Finally we have a growth curve tyrannosaurus “We can feel confident,” she says.
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