For a long time, Tyrannosaurus rex, or T. rex, was imagined as a terrifying predator that reached its full size in a short period of time. However, a recent study has revealed that in reality, T. rex grew much more slowly. The research shows that it took a T. rex about 35 to 40 years to reach full adulthood.
The fastest growth phase of their lives occurred between the ages of 14 and 29. During this period, their body weight increased by approximately 800 to 1,200 pounds per year. After that, over the next 10 to 15 years, their body size and strength continued to increase gradually. This means that T. rex only became truly fearsome after passing a long adolescence and reaching middle age.
Researchers from Oklahoma State University in the United States analyzed fossils of 17 T. rex specimens collected from museums in Montana and North Dakota. By examining growth rings inside the leg bones under special light, they were able to determine the dinosaurs’ age and growth rate. These rings, similar to the annual rings of trees, provide clear evidence of yearly growth and pauses.
This study has encouraged scientists to rethink their previous assumptions about the lifespan, growth, and behavior of T. rex.