Study finds Tyrannosaurus rex did not reach full size until age 40The study used a new statistical approach that considered growth records from different specimens to better estimate the growth trajectory of the species across all stages of lifeBy Will Dunham / Reuters, WASHINGTONThere is no question that Tyrannosaurus rex got big. But the question of how quickly T. rex achieved its maximum size has been a matter of debate. A new study examining bone tissue microstructure in the leg bones of 17 fossil specimens concludes that Tyrannosaurus took about 40 years to reach its maximum size of roughly 8 tons, some 15 years more than previously estimated. “Scotty,” the largest known Tyrannosaurus rex specimen, exhibited in Japan in this undated photo. This study involved more Tyrannosaurus specimens — many of them held at the Museum of the Rockies in Montana — than previous research into the life history of this species.
