![]() Nor can you compare a two-legged dinosaur to a four-legged mammal of the same mass and suppose they must have moved at similar speeds. It's not good enough to say that because a bone is big, with plenty of room for big muscles, that those muscles and bones were built for speed and not for support or other functions. Urifortunately, we don't know enough from looking just at bones to be able to tell how fast T. Scientists look for ways to test a hypothesis like the idea that T. Otherwise, as Ralph Molnar says, we could all be philosophers and not have to grub around in the dirt doing messy research. Just because something sounds logical doesn't mean it is true. And like much of what Bob has to say, I think his estimate of T. He makes a lot of intriguing statements that get other scientists riled up, and sets them to work disproving him. rex, according to Bob, could run forty to forty-two miles per hour. Bob says he's driven a jeep in Africa at twenty-eight miles an hour and not put any distance betweeen himself and a white rhino. That's more bone strength per pound, Bob argues, than a white rhino. Its thigh bone was indeed massive, seventeen inches around.īob then contrasts that thigh dimension with his estimate for the weight of T. rex hasĪ large bone surface below its knee, the attachment point for a huge mass of muscle that would have propelled it quickly as a runner. The new image of the hot-running dinosaur was popularized by Bob Bakker. rex is the swiftest of the swift- Carl Lewis in lizard skin. Now that so many people think of dinosaurs as hot-blooded speedsters, T. rex the fiercest of a stupid bunch of sluggards, it didn't need to be very fast to survive. Then we'll be smack in the middle of a good, long-standing argument about dinosaur speed. rex might have run is something we'll be able to do better after fully measuring Kathy's T. rex's bones and some pretty sophisticated thinking, we can make some reasonable guesses about how fast this dinosaur moved. rex could probably run a lot faster than a crocodile. With its long and powerful legs and its balanced two-legged stance, T. And crocs can go at a pretty good clip, even gallop with a bent-leg waddle. Crocs don't drag their tails when they run-they keep them raised. You have only to look at crocodiles in the swamp to picture the tail of T. rex striding along with its tail held out behind it. Swish it around for balance (even use it as a weapon) when it ran. rex, the largest of the cats, the tiger, looks like a tabby. rex weighed little more than a bull elephant, but it was considerably longer. rex would have been able not only to keep its tail well off the ground, but to That's negative evidence, the worst kind, but it still suggests that most dinosaurs kept their tails up. And we see prints of a dragging tail on some of only the earliest of the many dinosaur footprint sites. Those muscles would have been sufficient to keep the tail off the ground. There were huge transverse processes, grooves and buttresses on the individual tailbones that would have supported large muscles. But how did it end up? At our museum, we have only the proximal half of the tailbones from a T. And the tail, which emerged from the pelvis, would have started out from the body well off the ground. With the body horizontal, the pelvis had to be aligned parallel to the ground. rex's neck drew its huge head farther back toward the hips, a way of pulling the center of gravity back, so the animal wouldn't fall forward. Some curve in the neck is a feature common to many dinosaurs-one of the things that sets them apart from other animals. rex, the bones show an S-curve in the neck. And Peter May, who built the exhibit, had to do a fair bit of bending and pulling to get the casts of the bones of Barosaurus to fit the desired pose.Īs for our T. It's also an unlikely pose for a huge dinosaur in life, as the scientists at the American Museum would tell you. Defending its young from a hungry Allosaurus, that huge plant-eater is rearing up on its hind legs with its neck held high, like Flicka on the old horse movies, only a lot more impressive. A good example is the dramatic new Barosaurus mount at the American Museum of Natural History. You can make a skeleton, and better yet a cast, go wherever you want it to by forcing and bending. rex's bones back together, there aren't a lot of ways to get them to fit. rex's complete skeleton, something only lately possible. And to make an informed guessĪbout either, you need to take a close look at T. You can't answer one of these questions without addressing the other. ![]()
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