News Paleontology

Growth Spurt: Teenage tyrannosaurs packed on the pounds

By Sid Perkins

- More than 2 years ago

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.

GRAND OLD SUE. Growth rings in a rib (inset) from the large tyrannosaur named Sue suggest that the creature stopped growing and then lived another 9 years.