Thursday, June 07, 2007

T. Rex Speed

Here we go again- another piece of research that aims to prove that all of our notions about the T. Rex are wrong, wrong, wrong.

T. Rex was no slacker. But the popular image of a nimble predator turning on a dime and chasing down prey with lightning speed is fiction, new computer models show.

The terrifying tyrannosaur was actually a slowpoke.

Which, of course, raises the question- what was the computer model based on?

To get a better estimate of the giant's movement, the new study modeled a typical complete T. rex skeleton, which probably weighed between about 13,000 and 17,000 pounds, and estimated its center of mass and the inertia, or resistance to movement, that it would have had when the animal turned or pivoted.

For example, an elephant's four tree trunk-like legs keep its center of mass over its feet, while T. rex would have had to balance its mass differently over its two small legs, bending them to keep from toppling over.

No mention of the Rex's big, heavy tail which palaeontologists think was a counter-balance for its body but okay so far. And an elephant can move at about 25mph too- but there's no mention here of the structure of the T. Rex's slender leg or articulated foot. I hope that their computer model took that into consideration.

The model results, detailed in the June 21 issue of the Journal of Theoretical Biology, also showed that T. rex would have had considerable inertia preventing it from turning quickly; a 45-degree turn would have taken one or two seconds — far longer than for a human.

Much like modern predators and their nimble prey which try to out-manoeuvre them by twisting and turning. Good thing that all those Cretaceous humans were able to turn quickly, huh?

These calculations lend further support to previous research indicating that the large tyrannosaurs could run no faster than 25 mph (and certainly not the 45 mph seen in some movies), because its leg muscles weren't big enough for fast running.

Never mind that we can't actually say exactly how big their muscles were. There's big debate about T. Rex speed but the arguments are a little broader than this article implies. We'll get to that in a moment.

"We now know that a T. rex would have been front heavy, turned slowly and could manage no more than a leisurely jog," said team leader John Hutchinson of the Royal Veterinary College.

Now, this research may actually be close to the truth- of course unless we develop time travel or make our own Jurassic Park we'll never know 100% just how fast the King of Dinosaurs was- but this article is so sloppily presented that it boggles the mind. They're postulating 25mph for a predator that was 40 feet long and weighed in the region of 7 tons. The T. Rex could deliver greater bite force than any other dinosaur. It's very short fore-limbs were not vestigial in any way but show areas for large muscle attachment- it's theorised that they were small in proportion to the body to reduce the weight at the front of the body and strong enough to grasp prey while the Rex delivered a killing bite. And no mention of the stiffened tail which was a counterbalance for its weight and could also have been used to help it turn rapidly- Tyrannosaurus was part of the group of dinosaurs called tetanurans, stiff-tails.

Previous research which has focused on the T. Rex's speed and which has concluded that it was slow, put its pace in the region of 11mph. Those who claimed the T. Rex was fast put it's speed between 25mph and 45mph. So this research doesn't paint the T. Rex as a "slow poke" but as a fast predator if we compare it to earlier work. To compare with a modern predator a grizzly bear can move at up to 30mph- I've seen these bursts of speed on nature documentaries and that hellishly fast. Now imagine a beast the size of a T. Rex going 25mph. Not fast if you're driving a car perhaps but moving on foot? The best Olympic sprinters can move at that pace- and only for short periods of time. The average human running speed is around 12mph- and I'd say that the vast majority of humans couldn't hold that pace for long. What really needs to be said here is that this claimed T. Rex speed would actually make it faster than the majority of other dinosaurs on which it would prey. In short, this research doesn't prove that the T. Rex was slow unless your basis for scientific knowledge comes entirely from Steven Spielberg- if we compare it to other work carried out by palaeontologists, this actually finds that the T. Rex was pretty speedy. Not so much as some have claimed but as the pace they're suggesting lies between the two extremes that are sometimes put forward I'd hazard a guess and say that they might actually be onto something.

I'd like to see team leader John Hutchinson moving at a leisurely 25mph jog. With a T. Rex behind him.


Bag said...

These things change all the time. Soon we will find one that crashed into a wall and the speedo will be stuck on 51mph. Then there will be adjustments to the models and things will change.

This is what science is all about.

Anonymous said...