Wednesday, June 06, 2007

T.rex Didn't Turn On A Dime

A 3D interactive method for estimating body segmental parameters in animals: Application to the turning and running performance of Tyrannosaurus rex. 2007. John R. Hutchinson, et al. J. of Theoretical Biology 246: 660-680.
Scientists have used detailed computer models to work out the weight of a typical "king of the dinosaurs", and determined how it ran and turned.
From the BBC:

The results indicate a 6 to 8-tonne T. rex was unlikely to have topped 40km/h (25mph) and would take a couple of seconds to swivel 45 degrees.

The team's computer modelling system estimated the centre of mass position and the inertia (resistance to turning), which have ramifications for how T. rex would have stood and moved and what it would have looked like.

"We've shown there's no way it could weigh 3-4 tonnes as some people have suggested. It had to have weighed 6-8 tonnes,"

The study indicates the animal would have changed direction incredibly slowly because of its massive inertia, taking more than two seconds to make a quarter-turn. The species certainly could not have pirouetted rapidly on one leg, as popular illustrations have sometimes pictured it, and other large dinosaurs, doing.

More agile prey would have given the slip to a marauding T. rex quite easily, it seems.

"These were big clunky things - T. rex and the animals it probably preyed on. We have to slow down our view of that ecosystem," said Dr Hutchinson, who is currently lecturing in biomechanics at the Royal Veterinary College in the UK.
It’s raining here in Dinosaur Park so we’re back in the Field Station for an afternoon of talks from some of the assembled palaeo-brain trust. So, here’s a quick update. I’ll try to post some photos from the workshop later in the week.