T. rex, predator or scavenger?

Well, I pretty much beleive most of what you say (although some is alittle more fiction than fact, 'snapping Triceratops horns like twigs' and such.)

However, 70 mph??? That's faster than I normally drive to work!

Seriously, T. rex does not have to be super-fast and 'flatten' it's prey. Sure, it's large, but with the right coloration, and given the mostly dense forested regions of it's home turf (mostly large conifers, right?) then there's no reason to assume it doesn't just wait for the prey to come into range. T. rex could probably run at the original estimated 40 mph, but even that speed is risky. You are just worried about a possible broken neck. What happens if a giant 10-14 meter, 4-7 tonne, thick-bodied animal were to leave the ground and then land on only one of it's legs at 40 mph and instantly trying to stop? Hey, I can probably only run at .01 mph, and even at that speed, if I land of my foot wrong, it hurts! Imagine that kind of injury on a predator that requires to be in top shape to survive?

I'm not saying T. rex can't run fast. Just that, when possible, it would avoid the effort.

btw, Triceratops horns wouldn't snap, since they're attached to the whole skull. Instead, a ceratopsian might receive a bad whiplash at most. Of course, a T.rex would not be stupid enough to attack any prey animal head-on. Instead, as most evidence points out, it would attack the sides or legs.

K. Szoke

I'm not saying that the Tyrannosaur would be running through open plains at 70 mph, only that if you gave it the 'run-way-space' it could concievably reach such a speed, although I doubt it would have any need to other than to possibly 'flatten' something really huge like a Brachiosaur. Not saying it *did*, just presenting a possibility as to its hunting tactics.

Personally I think the ambush approach or the komodo-dran tactic (wounding prey and following it) are the most likely.

Just curious, how do you know that T. rex could reach such a high speed? Ostriches are much more lightly built than T. rex, and the ostrich can only reach speeds of up to 44 mph. A cheetah can top out at 70 mph for brief periods, but it is the fastest animal known, and it is also much more lightly built than T. rex.

'Robert Bakker (1986) has asserted that six-ton Tyrannosaurus could move at 75 kilometers (45 mi.) per hour. As John Ostrom notes, 'A six-ton elephant might reach eighteen miles an hour running full speed, downhill, and a half-ton Thoroughbred might-just might-hit forty miles an hour on a level straightaway. Bearing this in mind, the notion of six tons of dinosaur flesh being routinely propelled at forty-five miles an hour is preposterous' (1987b, 63).'' (Feduccia 1996:120)

The Tyrannosaur could 'speed-walk' at 45 mph. That is estimated by its leg spread and muscle mass in its legs. Yet even at this speed, at least one foot will be touching the ground at any given time....when an animal 'runs' (goes through a 'step' where both feet completely leave the ground, interspersing the steps in which each foot is touching the ground) it goes much MUCH faster.

90 mph is only double the Tyrannosaur's speed-walk, which would make it a truly pathetic running speed for Tyrannosaurus. 70 mph would be the Tyrannosaur equivolent of a brisk jog, and is therefor a very VERY conservative maximum velocity for the animal.

Unless you would like to argue that the Tyrannosaur was incapable of running at all? You may as well not even classify it as a therapod,

It could? Says who? Any references?

But how about any measurement on how fast T. rex can move those legs?

How many times per minute would T. rex have to move its legs to achieve this type of speed?

Theropods can run, but not at the speed that you imagine.

As far as I know no scientist who has studied the question has ever claimed that T. Rex could run faster than 45mph, and most believe its top speed to be significantly less. Why do you believe you understand this question better than they do?

I can, seeing as any _Utahraptor_ that _T. rex_ would have come across would have been dead for over 50 million years.

That's another problem with the idea of _T. rex_ being an obligate scavenger, actually

There you go being picky again! Whats a mere 50my amongst friends! Anyway I bet that Utahraptors ate stylishly slow and liesurely. . . .It could happen! )))

Getting back to your point, if you look at the adaptations of the ceratopians for 'duking it out' and the hadrosaurids for getting out of Dodge (and possibly breeding like rabbits based on the reported clutch size), there had to be some very good reason for expending all of this energy and favoring all of the massive armament, and Im for betting that he had some big, sharp, serrated. steak-knife teeth and little stubby arms.

That gap between the big Tyranasaurids and the little flesh eaters doesnt quite feel right either. If you look at the African savana, there are no 'one size fits most' predators. You start out at the lions, hit the leopards, the cheetahs, the hyenas, the hunting dogs, etc, etc, etc. Its not that a lion wont take a small gazelle (if it can catch it!) , just that the cheetah does much better with that kind of little agile prey!

Didnt I see something about some sort of 'pygmie' tyranasaur, IIRC, in the 10-15 ft long size? Could it be that either dwarf tyranosaurs (or possibly just the juvenile T. rexes filled in the gap for predator size?

Regards

Do you have a reference for this? The 9mph sounds right to me, but a walking speed of 40 mph????

And how many ambush predators have legs as proportionally long as those of tyrannosaurids, with a special modification (arctometatarsaly) for cursoriality?

Ummm... .

Not according to the study that was done.

Whoah there

: *could* run.

That's silly. Everyone knows that if Tyrannosaurus rex could run that fast, it would have caught the Jeep in 'Jurassic Park.'

Sean Barry

Snippage. . . . . .

I tend to agree with you on this one, but one of the surest signs of 'pseudo science' is clinging to an concept too long after the cards start going against it. Know when to hold 'em and KNOW WHEN TO FOLD 'EM. . . . . .

Regards