Dinosaur story: Researchers claim T. rex took 40 years to grow, much longer than previously thought

New Research on Tyrannosaurus Rex Growth

A study conducted by researchers has revealed new insights into how long it took Tyrannosaurus rex to reach its full size. Surprisingly, it seems that this process took about 40 years, which is notably longer than the previously estimated 30 years.

This dinosaur, known as one of Earth’s largest land predators, has been the subject of new findings published in the journal PeerJ. Holly Woodward from Oklahoma State University, who led the study, described the growth rate as “slower than expected.”

“Tyrannosaurus didn’t just quickly become an adult. Instead, it spent a large portion of its life as a juvenile or subadult,” Woodward explained.

The study involved analyzing bone tissue from the foot bones of 17 fossilized tyrannosaurs. The team discovered that these dinosaurs took roughly 40 years to grow to their maximum weight of about 8 tons.

Paleontologists have historically believed that full growth occurred within about 30 years. However, the researchers found that some bone growth patterns were only detectable under polarized light.

Some of these growth markers were visible on leg bones, showcasing annual growth similar to tree rings. Interestingly, they examined both juvenile and adult specimens.

“The spacing of the growth markers varied between individual tyrannosaurs,” Woodward noted.

Jack Horner, a co-author from Chapman University, indicated that this newer estimate was derived from a fresh statistical method that integrates growth records from different specimens. “While we can’t be absolutely certain, these new estimates appear more logical and statistically sound, given their size,” he mentioned.

The growth rate likely varied based on environmental conditions and available resources, Woodward added. “If conditions weren’t favorable, they wouldn’t expend as much energy on growth. However, if conditions improved, that could lead to more rapid growth,” she explained.

This adaptability in their growth might have supported Tyrannosaurus in outgrowing other carnivores, enabling them to compete effectively for resources. After all, T. rex wasn’t just facing other species; it had to contend with its own kind for food.

Fossil evidence shows that T. rex could grow over 40 feet long, boasting an impressive bite force.

Tyrannosaurus rex roamed western North America during the Cretaceous period, and these formidable creatures met their demise roughly 66 million years ago due to an asteroid impact on the Yucatan Peninsula.