Tyrannosaurus rex Teenage Growth Spurt

For years, paleontologists thought a teenage Tyrannosaurus rex went through an extreme growth spurt as it raced toward adult size. Studies based on growth rings in fossil bones suggested that young T. rex could pack on about 35 to 45 pounds a week during adolescence. That made the animal seem like a giant predator that shot up to full size in a surprisingly short time. But newer research published in 2026 suggests T. rex may have grown more slowly and stayed in its subadult stage much longer than scientists once believed.

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