Growth Spurt: Teenage tyrannosaurs packed on the pounds
By Sid Perkins
Detailed analyses of fossils of Tyrannosaurus rex and some of its more ancient kin suggest that the creatures experienced an extended surge in growth during adolescence, putting on as much as half their adult weight in a mere 4 years.
T. rex, one of the most fearsome meat eaters ever to stroll the planet, weighed more than 5,000 kilograms as an adult. Scientists have long debated whether such large dinosaurs achieved their bulk through rapid growth when young, delayed adulthood that enabled a longer growth period, or both. After scrutinizing the remains of four tyrannosaur species, researchers suggest that the beasts went through a substantial teenage growth spurt.