Johnny Cash might have said, life wasn't easy for a dinosaur named SUE. She grew up quick and she grew up mean, packing on nearly 4000 pounds a year as a teenager.
"We estimate they [Tyrannosaurs] grew as fast as 3,950 pounds per year (1790 kg) during the teenage period of growth, which is more than twice the previous estimate," said John R. Hutchinson of The Royal Veterinary College, London in a press release.
Modeling the teenage growth spurts of an ancient mega-predator was made possible by comparing computer models of smaller, younger Tyrannosaurs with those of full grown adults, including the tyrant lizard queen, SUE, the largest T. rex skeleton yet discovered.
The new models also found that the 42 foot-long SUE may have been much heavier than earlier estimates. She tipped the scales at approximately 9 tons, according to the computer model.
"We knew she was big but the 30 percent increase in her weight was unexpected," said co-author Peter Makovicky, curator of dinosaurs at the Field Museum of Natural History in Chicago.