dinodamone wrote:I'm resurrecting this discussion and going back to the original subject: Tyrannosaurus Rex Is Not a Scavenger..
I watched a documentary (Horizons to be specific) about T-Rex. The theory had arisen in the programme that the Tyrannosaur is not actually a predatory hunter but a scavenger. I found it so interesting!
They commented on the fact that it's arms were so small that it is a very uncommon trait to see in any predator today, take the cheeter for example, who gets it's arms round a Zebra as it attacks. It was found that the T-Rex's arms made up only 2% of it's actual body length, where on comparison with a Velociraptor, whose arms made up 6% of it's body length, is quite a difference, given the size of it.
They also looked at the teeth, a Tyrannosaurs teeth are smooth to point whereas Velociraptor's are cerated like a knife or a sharks tooth.
This one guy, Jack Horner- believed that T-Rex was a scavenger because he was analyzing skeletons of the dinosaurs which had been killed by one and he found that where there were bite marks, it would've been impossible to bite unless already dead. He found the same thing on every dinosaur, so it looked like the animal had already been killed by something else, and T-Rex had come along and eaten the left-overs.
This other dude tried to prove him wrong by saying that he was analyzing a Herbivore's vertebrae and there were half bones where T-Rex had obviously bitten through bone but on TOP of the skeleton. I thought, bullSHIT.. T-rex could've bitten that when it was lying down. Lame theory!
On the arms...
There's a difference in hunting style between a cheetah, Velociraptor, and Tyrannosaurus, however. A cheetah tackles its prey in mid-sprint, needing its forearms because it can't rightly take down a wildebeest at high speed with just its jaws. A Velociraptor uses its claws to both anchor itself to a larger prey, as well as rip & tear it until it bleeds out. Most large carnivorous dinosaurs, however, did not hunt with their forearms. Allosaurus, Tyrannosaurus, Ceratosaurus, Carnotaurus...these animals rely on their bulk and the strength of their head & neck muscles to basically bowl the target over. For these animals (even the Carnosaurs, who had decidedly large arms) to use their forearms would be impracitcal, because there's no way in hell even an Allosaurus could
hold a multi-ton juvenile Sauropod. So evolution naturally phased the unnecessary limbs out in later designs.
On the teeth...
Whoever said that T.rex's teeth were smooth is an absolute blind idiot. Just
look at a T.rex's tooth and you can clearly see the serrations. Not to mention look at just how much is rooted back into the jaw. These teeth were wide, serrated, and deeply anchored into the skull, all of which are characteristics of teeth used to kill. When combined with the T.rex's incredibly powerful jaw muscles, you have the sort of bite that would be
utterly unneeded in the mythical "pure scavenger."
On the angle of T.rex's bite...
This means nothing, really. There was an Edmontosaurus annectens skeleton discovered once with bite marks of a T.rex on some vertebrae at the base of the tail. Thing is, these vertabrae showed signs of healing. Dead things don't heal...the T.rex bit into a
living Edmontosaurus' back, the animal got away, and lived long enough for the damage done to the bones to crookedly heal.
As for bite marks that would have been impossible on a living animal...well...yeah...after you make a kill, you tend to eat it. This involves gnawing...on a carcass...one you yourself might have killed.
To say an animal is a "pure scavenger" is to say you have a living unicorn in your back yard. They're both mythical beasts. All predatory animals survive through a combination of hunting and scavenging. Fresh meat (a hunted kill) is preferred, though when easy prey is on short supply, a predator will not be above scavenging a kill. Lions hunt, yet also scavenge. Hyaenas scavenge, but also hunt. Tyrannosaurus is just like these animals. When it could make a kill, it made a kill. When easy prey wasn't around, it looked for a corpse.
Another flaw in the "pure scavenger" idea is that there couldn't have been enough corpses just conveniently lying around to satiate an entire population of eight-ton carnivores. Sure, nature is a cold and unforgiving place, but I doubt there was enough death going around to properly supply a massive eating machine with enough food to last it a lifetime. Ergo, hunting in conjunction with scavenging
was a necessity.
T.rex did both. As does every meat-eating animal today, and every meat eating animal in the past (yes, Raptors scavenged...shocking, ain't it?).