T. rex's tail made it speedy

No wonder his mate was always pissed.

Speedy like a chicken!

"Ribs were much higher on the tail" I think they're talking about the spine here.

"Ribs"

Speedy being a totally subjective term. I think I heard something along the lines of a running speed of 16 KPH but certainly nothing close to the 60 KPH portrayed in Jurassic Park.
And while this particular discovery is pretty cool, dino-paleos have been suggesting, based on skeletal and muscular systems, that T-Rex was far more than a plodding, lumbering scavenger for at least 10 years now.

I have NO idea why I had a double post at the beginning.
This last one REALLY has me wondering.

Yeah yeah sure you post ho'

WTF is happening with my posts in this thread???

Only 16kph? How far?

And why wouldn't an animal with that kind of musculature and range of motion not be able to achieve 60kph?

Only 16kph? How far?

And why wouldn't an animal with that kind of musculature and range of motion not be able to achieve 60kph? Ok first off, I erred, it was 16 not Kph
Now, from a purely evolutionary perspective, T-Rex only had to run fast enough to catch its prey, primarily hadrosaurs and ceratopsians, which theoretically weren't all that fast.
Secondly, while some studies have shown that T-rex could have potentially reached 40 Kph, it's also been put forth that to reach those speeds the leg muscles would have to account for at least 40% of its body mass in each leg.

However, studies done earlier this year now bring back the suggestion that T-rex was relatively slow. Based on the speed of nerve signals(55 meters/sec) a large animal like an elephant(or dinosaur) would effectively be running blind, ie; their brain wouldn't receive the signal their foot touched the ground until AFTER the foot was on its way back up again. This suggests that T-Rex was unlikely to be a sprinter and probably only ran rather short distances when it was absolutely necessary.
It's also been known for a long, long time that the bigger an animal gets, the slower it becomes relative to its size. And if they get REALLY big, they can't really run at all. If we go back to the elephant, when they "run", it's more like a quick shuffle as their feet barely leave the ground.
Now, when you look at a T-Rex leg it has a long thigh bone and a short shin bone. The reverse is usually true of the animal kingdom's fastest runners. As a matter of fact, T-Rex's leg more closely resembles a human leg, and we're definitely on the slow side of the scale by animal standards.
And finally, because of T-rex's centre of gravity and mass, it would take a full 1-2 seconds for it to turn its body just 45 degrees. This shows a neither particularily quick or agile animal.
So in conclusion, based on a variety of known sources(if yer into dinosaurs they're known anyway ), I believe T-rex wasn't all that fast simply because it didn't to be all that fast. And like many apex predators, while it probably was a more than adequate hunter, it also wasn't gonna turn its nose up at a free meal that something else killed if it meant expending less energy. It certainly had the intimidating size and maw to pull it off.
In other words, it would hunt and kill its own prey if it had to but probably preferred pilfering someone else's