Turns Out T. Rex Wouldve Broken Its Tiny Legs If It Tried To Run, Contrary To Jurassic Park TIME

[yuiyoshida]

[Old Crow]

1. Huh. Still processing this...

There have been so many revisions to our understanding of the T-Rex in my lifetime. The scientists have made a lot of progress these past few decades, it seems. Thanks, Yui!

[BumRushDaShow]

2. I was just looking up what was out there about elephant speed

and found this from 2003 (which relates to the OP too) -

Speedy elephants use a biomechanical trick to 'run' like Groucho

A study published in the April 3 issue of Nature solves a longstanding mystery about elephant speeds by clocking the animals at 15 miles per hour. That's faster than reliable observations of 10 mph top speeds but slower than speculations of 25 mph. But do fast-moving elephants really "run"?

Even at fast speeds, it might seem to the casual observer that elephants don't run. Their footfall pattern remains the same as that in walking, and never do all four feet leave the ground at the same time -- a hallmark of running. But biomechanists are finding that an elephant's center of mass appears to bounce at high speeds. If that turns out to be true, an elephant's gait meets the biomechanical definition of running.

Biomechanists have dubbed this gait "Groucho running" after the silly, crouched walk of Groucho Marx. They say the elephants seem to bend their limbs slightly in order to move their bodies more smoothly. This research may provide insight into the biomechanical tricks that help large animals, from extinct dinosaurs to obese people, overcome the physical forces that restrict their motion.

"We do find evidence that elephants run in a sense," said first author John Hutchinson, a Stanford postdoctoral research fellow in the Department of Mechanical Engineering. "It's an intermediate sort of gait, but it looks like what we biomechanically would call running. They don't leave the ground, which is the classical definition, but they do seem to bounce, which is the biomechanical definition."

<...>

http://news.stanford.edu/pr/03/elephants49.html

[Old Crow]

3. Good find.

It makes sense that the T-Rex would have developed some particular gait, as the elephants have, to maximize speed while keeping forces on the leg bones within acceptable levels.

I think it's also worth noting that the 12 MPH speed calculated by the scientists for a T-Rex would be faster than most humans can run. It may be "slow," buy obviously speed is relative.

[BumRushDaShow]

4. As a former recreational bicyclist

about 20-some years ago, my average consistent speed was about 10 - 12 mph, where I could briefly "sprint" to about 25 mph, and could accelerate to 35 mph going down hills. So yeah, that speed ain't bad at all!

[cab67]

5. A couple of points here:

1. The conclusions in the recent study aren't really all that novel. We've known that the top speed for T. rex was comparatively low for many years. The new study uses different methods, but it comes to basically the same conclusion.

2. Jurassic Park actually got it more or less right. If you look at the T. rex in any of the movies, it never actually runs in the strictest sense of the word - it always has one foot on the ground. It's walking quickly, not running. The error was showing it catching up to a Jeep, but not because it had the T. rex running (it didn't), but because it implied an anomalously slow speed for the Jeep.

[Old Crow]

8. Interesting, and what you're saying makes sense.

Thanks for the insights.

[Roy Rolling]

6. Show proof

To substantiate this theory, are there fossils of T-Rex with a broken leg?

[cab67]

7. This would be part of a paradox.

Most fractures would be indicted by evidence for healing. Whether a broken bone without healing was fractured at/near the time of death or from scavenging, trampling, or some other postmortem process would be difficult to tell.

Fossil animals with lots of healed trauma were actually very healthy animals - sick animals tend to die before their skeletons can respond to a fracture or infection.

All this said - I've seen pathological tyrannosaur hindlimb bones, but nothing to indicate a major incapacitating fracture.

[Thor_MN]

9. That's a ridiculous argument.

Your claim assumes that T Rex did indeed run, even if it would break it's legs in doing so. And that there is no other way a T Rex could break it's legs.

One might as well declare that every broken human leg is caused by jumping from a height of 40 feet or more, since studies indicate the forces generated would fracture leg bones.