
T. rex Rewrites Its Growth Timeline: Adulthood Arrives at 35–40
A peer‑reviewed study analyzing growth rings in 17 T. rex leg bones shows full adult size was reached around ages 35–40, with rapid growth from 14 to 29 and extended growth for at least a decade afterward, implying a longer subadult phase and prompting renewed questions about species boundaries within fossils labeled T. rex.
