T. Rex May Have Been Bigger Than Thought

A teenage T. Rex grew as fast as 3,950 pounds per year!

ScienceDaily — A new study reveals that T. rex grew more quickly and reached significantly greater masses than previously estimated. In a departure from earlier methods, the new study uses mounted skeletons to generate body mass estimates.

In a new study just published in the online journal PLoS ONE, a team of scientists led by Professor John R. Hutchinson of The Royal Veterinary College, London, and Peter Makovicky, PhD, curator of dinosaurs at The Field Museum of Natural History in Chicago applied cutting edge technology and computer modeling to "weigh" five Tyrannosaurus rex specimens, including The Field Museum's iconic SUE skeleton. Their results reveal that T. rex grew more quickly and reached significantly greater masses than previously estimated.

In a departure from earlier methods, the new study uses mounted skeletons to generate body mass estimates. Makovicky notes, "Previous methods for calculating mass relied on scale models, which can magnify even minor errors, or on extrapolations from living animals with very different body plans from dinosaurs. We overcame such problems by using the actual skeletons as a starting point for our study."

The team used 3-D laser scans of mounted skeletons as a template for generating fleshed-out digital models whose masses could then be computed. The laser scans are accurate to less than half an inch for skeletons that are up to 40 feet long. Digital body cross-sections were reconstructed along the length of each skeleton using the relationships of the soft tissues to skeletons in birds and crocodiles as a guide. A digital skin was then overlaid to generate a body volume, whose mass was calculated after empty spaces such as lungs and the mouth cavity were modeled and subtracted.