T. rex was

I needed a good laugh today. 'Impossible' for T. rex to move 45 mph? T. rex could have done that without even running (at least one foot always on the ground). Well...let's see, if he could take one step per second at his fastest speed (which seems slow, even for an animal that big), that's still about 15 to 20 feet per second. What's the mph for that? If T. rex could even run at all, 45 mph seems about the slowest 'high speed' I could possibly imagine for the animal. Of course, I'm no biomechanic.

Well, I'm dubious of their analysis too, but 20 feet/second is only about 13.6 mph.

You have a short memory, don't you? We went through this all before. Bakker's estimate of 45 mph is the absolute top speed that anyone has *ever* seriously proposed for T.rex; even before this new study everyone else who ever looked at the question has come up with a number significantly lower. For you to set 45 mph as a *lower* limit, based on your own half-assed calculations, is just plain foolish. This new study might be right or it might be wrong, but at least it was done by people who had some vague idea what they were doing.

That about sums it up, doesn't it ?

chortle chortle

john thrum

Personally, I like Bakker's estimate of 45 mph top speed for the T. rex, although I would have to suggest that the occasional forward lunge (if T. rex were an ambush predator) could have possibly gotten him up to 60 for about a split second...or maybe even a second and a

All I'm saying is that I have a hard time believing that the rex was incapable of getting up to 45 mph. I'm not a biomechanic, but I find it really hard to swallow. I'd have an easier time believing that an Eagle's wings are only useful in breaking a fall, rather than for true

I never claimed to be an expert on T. rex. I never claimed to be an expert on paleontology (other than being an interested amatuer). All I ever claimed is that to an amatuer like me, it seems a bit hard to swallow that an animal with 5 times the stride length of any human could only run about the same speed, and that the animal is considered a predator when animals like Giganotosaurus, who are heavier, about the same length, and shorter at the hip with stumpier legs, are considered predators.

The Gigantosaurus was probably also as heavy and ponderous as TRex. Trex was just an example used in this study.

Can you not imagine that these were different times back then? Everything was big, and everything was ponderous. The predators simply didn't need to move at high speed, because its prey didn't. Trex and Giganto were probably specialized in hunting big prey, and big prey only.

There were probably small and fleet-footed creatures around at this time, but Trex never bothered with them because: (1) they were too fast, and (2) they were too small to fill its stomach. We too see echos of this divergence today in our own lives, because we're the large animals of today, and at a much smaller scale of life, like insects, the pace of life is truly furious compared to ours.

So forget about dreams of going back in time, and meeting up with a Trex and being chased and having to outrun it. Trex probably wouldn't even look at you twice

You know, that article is sort of interesting. The researchers used their 'analysis' to determine the potential speed of an essentially unknown animal, the T. Rex, get credit for publishing the results. Stir up a regular little donny-brook on one of the most heatedly debated topics in paleontology. Grab their moment of fame, and THEN decide to get around to 'calibrating' their analysis methodology against a modern elephant! Of course the modern elephant is a quadrupedal mammal. . . . .still the mechanics should be at least somewhat related.

IF the analysis of the elephant reveals that the poor animal should just lay down and die, unable to even rise off of the ground, where does that leave the T. rex 'analysis'? Oh well, thank goodness for the English trackways that show a medium tyranosaurid trucking along quite nicely, thankyou! Again it would be REALLY nice to see what the analysis has to say about this smaller British theropod! Clue, if it doesnt come pretty close to the quite factually, 'written in stone' answers, the analysis might need some analyzing! 8-) Again since we are rather short of bipedal animals over the weight of a human, those trackways that show 'running' theropods just might be a way to tighten up the calibration (and credibility!) of this study!

What can I say! Im a skeptic of analysis unless supported by HARD evidence! 8-)
www.cnn.com/2002/TECH/science/01/31/running.dinosaur/? related www.cmnh.org/fun/dinosaur-archive/2002Jan/msg01175.html http://www.stadiumweb.com/reprints/lockley1.html

Regards

Personally I don't see the rex ever having to move beyond about 26 mph...except if he were and ambush hunter (he could probably do better than 45 for a split second), or if he were fighting/preying and had to ram his soon-to-be victim. I see the rex as being easily able to facultate 25 or 30, but almost never going any faster, with a potential high speed of 45-50, or possibly even 60 for a bout two seconds during the climax of an ambush.

I once made some half-assed calculations based on comparing the Rex's walking speed (estimated at 9 mph) and that human's walking speed (2 mph), the maximum speed possible with one foot remaining on the ground (a speed-walk, about 45 for a rex and 5 for a human), and extrapolated that if a human tops out at 20 mph, a T. rex's maximum speed should come in around 180 mph...and that didn't even take into account that humans aren't built for speed like theropods are. Of course, one thing I did assume which I probably should not have is that a rex should be just as light on his feet as a Coelophysoid....after all, he was bigger, but he also had much larger, stronger legs, and small feet. Well, at least the bones were small....I wonder if there's been any tests done to see how 'springy' rex's feet were???

But Giganotosaurus? Let's see, 50 feet long (about the length of T. rex), 8 tons (a half-ton heaver than T. rex), and 12 feet tall at the hip (6 feet shorter than T. rex and therefor having stumpier legs and the same small arms)....and Spinosaurus? Give me a break! Out of all the giant-predators, T. rex is probably the least likely to have been a scavenger. I mean, sure, Giganotosaurus may have been a little bigger than a T. rex, just like a toad whose a little bigger than a road-runner. Spinosaurus may have been the same length head-to-toe as the Rex (maybe a teensy bit longer), but the sail on its back, the lightly built skull and the non-serrated conical teeth all imply that the animal was a fish/carrion eater, not to mention being about 2/3 the size of a T. rex.