Some revisionist paleontologists have claimed the T-Rex was just the "world's largest turkey buzzard", pointing to its massive olfactory brain center and its teeth which are more adapted to crushing bone than tearing flesh. They claim that it needed a very sharp sense of smell to find carrion, and that by being able to crush bone it was able to get nourishment other animals would leave behind, by eating bone marrow. This was coupled with studies which indicate it's unlikely the T-Rex could run at more than about 15 mph, far slower than modern top predators such as lions and tigers (and quite a bit less than the 40-to-45 mph seen in "Jurassic Park). They compared the T-Rex's keen olfactory sense with that of a turkey buzzard, which is a carrion eater. They claimed that the T-Rex lived exclusively on carrion, and the only reason it needed a large size was to chase off predators from their kills.
However, even when I saw this theory being propounded I thought their arguments were shaky. Comparing the T-Rex to modern top predators such as lions and tigers is rather pointless. Okay so the T-Rex couldn't run as fast as a lion. So what? It wasn't trying to run down antelope and zebras as lions do. Its most likely prey was large and relatively slow herbivorous dinosaurs. If its prey could only run at, say, 10 to 12 mph then 15 mph would have been quite fast enuff to run them down. And altho top predators today have teeth adapted to tearing flesh, unlike the T-Rex's bone-crunching bite, again I don't see that's any indication the T-Rex wasn't adapted to be a predator.
With its tall, upright stance and bone-crushing teeth, it would seem its likely hunting strategy would be to run up behind its prey and bite its backbone hard enuff to break it, thus paralyzing its victim. We do have one piece of evidence that a T-Rex tried this with a duckbill dinosaur; one skeleton was found with partially-healed holes in its backbone, and the holes were exactly the right shape and size for T-Rex teeth. The fact the wound was partially healed proves the bite was made while the duckbill was still alive. This is very strong evidence that at least occasionally the T-Rex hunted live prey, rather than depending on carrion.
A hunting strategy of running up behind/beside the prey and biting its backbone hard enuff to crush bone seems to me to be a relatively good hunting strategy. I think it's a much safer approach than, say, the cheetah, which has to bite its prey in the throat and hang on until it suffocates. [The prey, not the cheetah:)] This is quite dangerous and may cause the cheetah to be injured.
Since I saw that revisionist theory, I saw another paleontologist who disputed the revisionists' claims the T-Rex had poor eyesight. He pointed out that the T-Rex had very large orbits (eye-sockets) and therefore very large eyes-- as accurately depicted in "Jurassic Park"-- and quite rightly said that animals with large eyes have very good eyesight. It's not just that larger eyes naturally give better eyesight; it's an indication the critter has a large investment in good eyesight. Eyes (or at least retinas and optic nerves) are grown from fragile and hard-to-repair nerve tissue, so are easily damaged. If a critter doesn't have a need for large eyes, evolution will quickly shrink them.
But the fatal "stomp" on the revisionists' theory came for me just recently when I saw an interview with the "bad boy" of paleontology, Robert Bakker. He said the T-Rex had the longest hind legs in proportion to body length of any predator that ever lived. That clinches it-- evolution would not have selected such an extreme adaptation unless the T-Rex had a "need for speed"! Carrion eaters don't need to run especially fast. Predators do.
Now that's not to say the T-Rex never ate carrion, in the sense of stealing another predator's kill. After all, lions get *most* of their food by stealing hyenas' kills, so in that sense it can be said the lion is primarily an eater of carrion. But the T-Rex was clearly capable of running down and killing prey, just as lions are.
So T-Rex can proudly reclaim its throne as the all-time heavyweight champ of land predators, just as we envisioned them when we were growing up. But with one noteable change-- they were covered with feathers!
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Some revisionist paleontologists have claimed the T-Rex was just the "world's largest turkey buzzard", pointing to its massive olfactory brain center and its teeth which are more adapted to crushing bone than tearing flesh. They claim that it needed a very sharp sense of smell to find carrion, and that by being able to crush bone it was able to get nourishment other animals would leave behind, by eating bone marrow. This was coupled with studies which indicate it's unlikely the T-Rex could run at more than about 15 mph, far slower than modern top predators such as lions and tigers (and quite a bit less than the 40-to-45 mph seen in "Jurassic Park). They compared the T-Rex's keen olfactory sense with that of a turkey buzzard, which is a carrion eater. They claimed that the T-Rex lived exclusively on carrion, and the only reason it needed a large size was to chase off predators from their kills. However, even when I saw this theory being propounded I thought their arguments were shaky. Comparing the T-Rex to modern top predators such as lions and tigers is rather pointless. Okay so the T-Rex couldn't run as fast as a lion. So what? It wasn't trying to run down antelope and zebras as lions do. Its most likely prey was large and relatively slow herbivorous dinosaurs. If its prey could only run at, say, 10 to 12 mph then 15 mph would have been quite fast enuff to run them down. And altho top predators today have teeth adapted to tearing flesh, unlike the T-Rex's bone-crunching bite, again I don't see that's any indication the T-Rex wasn't adapted to be a predator. With its tall, upright stance and bone-crushing teeth, it would seem its likely hunting strategy would be to run up behind its prey and bite its backbone hard enuff to break it, thus paralyzing its victim. We do have one piece of evidence that a T-Rex tried this with a duckbill dinosaur; one skeleton was found with partially-healed holes in its backbone, and the holes were exactly the right shape and size for T-Rex teeth. The fact the wound was partially healed proves the bite was made while the duckbill was still alive. This is very strong evidence that at least occasionally the T-Rex hunted live prey, rather than depending on carrion. A hunting strategy of running up behind/beside the prey and biting its backbone hard enuff to crush bone seems to me to be a relatively good hunting strategy. I think it's a much safer approach than, say, the cheetah, which has to bite its prey in the throat and hang on until it suffocates. [The prey, not the cheetah :)] This is quite dangerous and may cause the cheetah to be injured.
Since I saw that revisionist theory, I saw another paleontologist who disputed the revisionists' claims the T-Rex had poor eyesight. He pointed out that the T-Rex had very large orbits (eye-sockets) and therefore very large eyes-- as accurately depicted in "Jurassic Park"-- and quite rightly said that animals with large eyes have very good eyesight. It's not just that larger eyes naturally give better eyesight; it's an indication the critter has a large investment in good eyesight. Eyes (or at least retinas and optic nerves) are grown from fragile and hard-to-repair nerve tissue, so are easily damaged. If a critter doesn't have a need for large eyes, evolution will quickly shrink them.
But the fatal "stomp" on the revisionists' theory came for me just recently when I saw an interview with the "bad boy" of paleontology, Robert Bakker. He said the T-Rex had the longest hind legs in proportion to body length of any predator that ever lived. That clinches it-- evolution would not have selected such an extreme adaptation unless the T-Rex had a "need for speed"! Carrion eaters don't need to run especially fast. Predators do.
Now that's not to say the T-Rex never ate carrion, in the sense of stealing another predator's kill. After all, lions get *most* of their food by stealing hyenas' kills, so in that sense it can be said the lion is primarily an eater of carrion. But the T-Rex was clearly capable of running down and killing prey, just as lions are.
So T-Rex can proudly reclaim its throne as the all-time heavyweight champ of land predators, just as we envisioned them when we were growing up. But with one noteable change-- they were covered with feathers!