T-Rex: Predator or Scavenger

[Saru]

This is a formal debate on the topic of whether or not the Tyrannosaurus Rex, the 'Tyrant Lizard', was a predator, or a scavenger.

The debate will be between two people, if you'd like to take part, please register your interest by posting a short message as a reply to this topic.

For full details on the way the debate system works, Click Here

[OpethBorgir]

Meybe they were both depending on the situation they were in.

[Saru]

Hi, are you interested in taking part in the debate or just commenting on the topic ? If you'd like to participate, post a quick 'i'm in' or something along those lines just to clarify if you'd like to give it a shot. Thanks.

[The Hunter]

I am. Dinosaurs are a main ground for animal life on Earth. T-Rex was a scavneger. The facts point to this from it's phsyical features. Small eyes, short arms, a big stance etc... gives the suggestion that it was a scavenger. Please pick me and I'll give clear and proper results!

[Saru]

Ok, now we need one more person for this debate.

[man_in_mudboots]

**screams at the top of his lungs**

ME!

Edited July 2, 2004 by man_in_mudboots

[Saru]

Ok looks like we have our two participants for this debate.

The results of the coin toss reveal that

The Hunter will be arguing for the side of the T-Rex being a scavenger

Man_in_mudboots will be arguing for the side of the T-Rex being a predator.

You are both allowed 5 posts, as well as an introduction and conclusion.

Good luck

[man_in_mudboots]

Well, to start, let me point out several features of the skeleton and compare them with successful scavengers of today.

-Tyrannosaurs have extensive muscle systems through out the jaw and skull (evident from the number and size of the attachment depressions in the bone) that would not have been needed, or would have been needed on a much lesser level, to crush the softened bone of dead creatures.

-the Tyrannosaurs naris (nostrils holes) are very far forward on the snout, even more so than most other dinosaurian predators, which is inconsistent when compared with the more successful scavengers of today; they normally have the nostrils farther back on the snout as the softer, more decayed gore tends to get clogged in their nostrils.

-olfactory lobes (the smelling parts of the brain) are very large. Paleontologists supporting the Scavenger theory say that this was to sniff out corpses, but it could have been just as, if not more, useful for smelling prey.

-the skull has several projections (like the supraoccipital crest and orbital brow bones), some of which were quite large and would have even been larger in life when a coat of keratin would have covered them. Scavengers usually have 'slicked down' skulls to burrow into the corpse, not projections which would get caught up and make this hard for a tyrannosaur.

-as herbivores got larger, so did the carnivores. Tyrannosaur’s large size would obviously have been unnecessary if it was a scavenger, it could have remained as small as the creature it evolved from originally or possibly even decreased in size, as it doesn’t take size to eat a corpse. Again, compare the scavengers of modern day with the scope of size in the age of the dinosaurs.

Now, many Paleontologists supporting the Scavenger theory point out that tyrannosaurus had small eyes, that they believe, would have been useless used for hunting down other animals, but let me point out that Dogs, Tigers, Lions, Polar bears, and many others have very small eyes for their size and are among the most successful predators on the planet. They have also said that Tyrannosaur’s small arms and hands would be useless for grasping, holding, and other similar purposes that could be of use in hunting. Dogs, Tigers, Lions, Polar bears, ect. seem to have gotten along fine with no arms or hands at all.

Paleontologists supporting the Scavenger theory continue to read false meaning into these facts, but Tyrannosaurus was obviously a hunter to the core. And no, im not saying this because a scavenger Tyrannosaur would have been a drag, im saying it because it makes perfect sense if you consider the facts!

Edited July 2, 2004 by man_in_mudboots

[man_in_mudboots]

oh damn, i forgot, i edited! mudboots, you idiot! how sadly typical of me.......

<-- that smilie pretty much sums it up here.

[Saru]

Its all right don't worry about it, you edited before your oponent replied, so you won't be disqualified for it.

The Hunter, you're up next.

[The Hunter]

Ahh, good points! Very scientific at that. Alot of reasearch time put in? Well my contradictions well better you ponits.

Scavenger or Predator?

Did Tyrannousarus rex pursue and kill live prey, or did it feed mainly on scavenged carcasses? The question has stirred many scientists and cause some plaentologists to re-evalulate T.Rex's status as the indisputable "tyrant king" of the dinosaurs. Here are some of the main areas of contention:

Sight and Smell:

In support of the scavenger theroy, scientists cite T. rex's relativley small eyes as evidence that it could not have been an effective hunter. Rather, its acut sense of smell- provided by a large olfactory lobe similar to vulture's - would have enabled it to detect carrion from far away.

Teeth:

Scavenger theorists contend that the rounded shape of the teeth- combined with its powerful jaws- was designed for crushing bones of carcasses and getting to the meat in less accesible areas. Other dinosaurs, like Velociraptor, had flat, knife-like teeth more suited to predatary attacks.

Arms:

Sacvenger thorists argue that the T.rex's short armswere too weak to aid in capturing and holding prey. Cats, dogs etc... use fore arms/legs to hold prey while attacking. They also use their arm/fore legs to position the prey during consumption. T.rex could not do this and it supports the scavenger theroy.

Legs:

Scientists differ on wither T.rex's giant legs were built to endure over long distances- necessary for scavengers to maximize the area of potential food sources or to providequick bursts of speed to chase prey down. That fact is still up for debate.

These facts all give way to the idea of Tyrannousarus rex being a scavenger, depending on other dinosaurs for a food source. Was it theses facts that overthrew the "tyrant lizard"?

(Was'nt that great? *Ego boost* Bring it on Man in MudBoots!)

The Hunter.

[man_in_mudboots]

Ahh, good points! Very scientific at that. Alot of reasearch time put in?

Thanks! I’m doing some research for this post, though. anyhooooo.....

Cats, dogs etc... use fore arms/legs to hold prey while attacking. They also use their arm/fore legs to position the prey during consumption. T.rex could not do this and it supports the scavenger theroy.

Hunter, I’m sure you have seen the famous museum skeleton recreation which shows a Tyrannosaur crouching over, gnawing on the bones of her prey, one foot on the ground and the other on the bones. Although I’m debating and not suggesting theories, I propose this: if Tyrannosaurus did, for some reason, need to hold its prey, he could simply put his foot on it as his leg was plenty long enough. Even though museum skeleton recreations are often incorrect and influenced by a sense for drama raher than science, this is definantly a resonalbe idea.

And please tell me how eating already dead things with short arms is easier than eating killed prey.

Scientists differ on wither T.rex's giant legs were built  to endure over long distances- necessary for scavengers to maximize the area of potential food sources

u.....I thought you were arguing for it being a scavenger?

or to providequick bursts of speed to chase prey down. That fact is still up for debate.

Now that’s more like it. Track ways have been found all over north Americaof Tyrannosaurus running, and one in Texas, is especially revelaing. Many notable Scientists have calculated that that particular Tyrannosaurus was running at between twenty and twenty-five miles per hour, which was surely enough to chase down a short-legged, tubby little Ceratopsian or a waddling Hadrosaurine. Bob Baker calculated it to be between thirty and thirty-five. You must consider that Tyrannosaurus wouldn't have needed to be a speed demon if he wasn’t chasing speed demons. I think you’ll agree that that’s a rule of evolution, never have more than is needed to survive, and Tyrannosaurus didn’t need more speed than they already had to catch their prey.

And last, studies by Bob Baker and crew have show that Tyrannosaurus would have had a very large lung capacity for its size, far larger than that of Allosaurus, which is commonly regarded as the true predator by those following 'the Horner mentality'. Does eating carrion require big, strong lungs? Heck no.

all in all, though, i had a hard time finding any holes there. you cover yourself well Hunter. you sweating yet?

[The Hunter]

Ha, good reply, but beat this. Your points are good, but very explainable.

One of the most famous people on the scavenger theroy is Jack Horner. The Montana paeleontologist , whose crew unearhted eight T.rex's in the past three years says that T. rex simply could'nt hunt.

Consider the beast's spindliy, little arms, stuck on to a stocky, 35 foot dinosaur. They could'nt have reached the mouth and would have been completely useless in a fight. Worse, if T.rex fell over or was knocked over, its delicate arms could do nothing to break its fall, and tons of dinosaur would fall to the ground, amid, snapping bones.

The dinsaurs mouth, raggedly spiked with huge, clylindrical teeth, could tear loose 500 pounds of of bone and flesh in a single bite. But, those teeth were designed fro crushing bones, not slicing through prime cuts of Triceratops. The first on the carcass gets the meat, scavengers will settle for the tough cartilage and bone.

Horner, paeleontogolgy curator at the Musem of the Rockies in Bozeman, Montana, made brain casts T.rex skulls and found a very, samlll optic region, but a huge offactory lobe. T.rex, he concludes, could'nt see very well, but could pick up on scents (pressumabley dead or dying beasts) at a great distances. The offactory lobe bears striking similarities to that of vultures, reputed for smelling carrion 25 miles away.

Horner also syas that T.rex's legs were ideal for long-distance walking, but grossly inefficient for running down prey: its thighbone is longer than its shinbone. Bipeadal predators typically have very short thighs andvery long shins, a combination that gives them great speed.

That is the case with late Cretaceous predators as Velociraptor, Deinonychus and Dromaeosarus. These were small (6-10 foot), bipedal killers with sharp, serrated teeth, powerful armstippd with vicious claws and a long sickle-like claw on each foot. Horner says they probably hunted in packs that could easily bring-down a six ton Triceratops.

"When you add up all the features of a velociraptor," Horner says " you come to the conclusion that it had to be a predator. If you add up all the features of a T.rex, it had to be a scavenger."

This is hardly a popular conclusion. Most of Horner's collegues are somewhat skeptical and legons of dinosaur fans are outraged. "People don't like it much," he says " But we are doing science here. Its not an opinion poll."

Horner's effective reasearch concludes that Tyrannusarus Rex was infact a scavenger. It is not up to people who enjoy filims like "Jurrasic Park" to say that he is wrong.

I hope everyone enjoyed my arguement and to Man in Mudboots, whos laughing now. And to your question, finding dead prey is far more easier then to kill, subdue and protect killed prey from other scavengers. Take some logic into your questions before asking again. I'm not to be messed with. And from the looks of my reasearch, it seems you'll be sweating now.

(P.S. Bob Baker is a hack, horner is forever! Just kidding!)

Edited July 5, 2004 by The Hunter

[man_in_mudboots]

First, let me point out that Jack Horner, on whom you have based almost all of your rebuttal, has himself admitted to being the king of ‘arm wavers’. By that he means people that go with what they have a hunch is right, even if there is very little proof. What everybody knows he is really saying is that arm wavers conclude things with no evidence at all, and bend the facts to mean what they want. Anyway..........

  Consider the beat's spindliy, little arms, stuck on to a stocky, 35 foot dinosaur. They could'nt have reached the mouth and would have been completely useless in a fight. Worse, if T.rex fell over or was knockedover, its delicatearms could do nothingto break its fall, and tons of dinosaur would fall to the ground, amid, snapping bones. 

Let me compare tyrannosaurus to some more modern predators. Secretary birds are renowned for their hunting skill, and they are.......birds........with no arms. They fall and get up fine. And they hunt and kill things as tall as they are and twice as stocky, with only their beaks and strength of their necks. Heck, chickens with their wing feathers completely cut off fall and get up fine.

Again, Allosaurus, which Horner considers to be the ‘real’ predatory tyrant lizard instead of Tyrannosaurus, had arms only slightly larger that Tyrannosaurus’s for its size. Were none of the large Theropods hunters?

And last, some Tyrannosaurs actually may have tripped, and couldn’t get back up until their prey had gotten away, but most predators have a very low success rate anyway. Just look at the cheetah chasing the antelope – eighteen out of twenty times the predator doesn’t get the prey.

  The dinsaurs mouth, raggedly spiked with huge, clylindrical teeth, could tear loose 500 pounds of of bone and flesh in a single bite. But, those teeth were designed fro crushing bones, not slicing through prime cuts of Triceratops. The first on the carcass gets the meat, scavengers get settle for the tough cartilage and bone. 

Indeed, Tyrannosaurus was the epitome of hunting. His teeth functioned as both steak knives when slicing was needed, and as mauls to break apart bone, as you just proved for me.

  Horner, paeleontogolgy curator at the Musem of the Rockies in Bozeman, Montana, made brain casts T.rex skulls and found a very, samlll optic region, but a huge offactory lobe. T.rex, he concludes, could'nt see very well, but could pick up on scents (pressumabley dead or dying beasts) at a great distances. 

Here we are again. Dogs have small eyes and relatively small optic lobes, and huge olfactory bulbs. And they’re obviously great hunters. Why you seem to think that good smell can only be used for sniffing out corpses, or why predators must remain entirely on sight, is beyond me.

Horner also syas that T.rex's legs were ideal for long-distance walking, but grossly inefficient to for running down prey: its thighbone is longer than its shinbone. Bipeadal predators typically have very short thighs andvery long shins, a combination that gives them great speed.

Again, I’m just repeating myself here, tyrannosaurus only needed to be a little bit faster than what he was chasing. The dinosaurs as a whole would have been slow because they were, warm-blooded or not, reptiles. The Ceratopsians and Hadrosaurines, Its main prey, would have been fairly slow.

This is hardly a popular conclusion. Most of Horner's collegues are somewhat skeptical and legons of dinosaur fans are outraged. "People don't like it much," he says " But we are doing science here. Its not an opinion poll."  Horner's effective reasearch concludes that Tyrannusarus Rex was infact a scavenger. It is not up to people you enjoy filims like "Jurrasic Park" to say that he is wrong.

How many times are we going to go through this, I’m not saying it because a scavenger tyrannosaurus would be a drag, I’m saying it because it makes sense.

and to Man in Mudboots, whos laughing now. I'm not to be messed with. And from the looks of my reasearch, it seems you'll be sweating now.

Calm down, man, I’m not messing with you. A part of debating is making it seem like the other fellow doesn’t know what he’s talking about, I’m trying to do it to you and your trying to do it to me, so don’t get p***ed off, its just another part of this.

------------------------

(and i know horner is a crazy radical, what can i say, do what you got to do to win this thing )

oh, and why dont we just edit our damn posts, niether of us can remember not to, and if were both doing it its plenty fair. we both know the others not going to cheat, right? thats such an annoying rule.

**looks under arms** nope, no sweat yet.

[The Hunter]

I think that we're just repeating ourselfs. Should we end it?

You stated that predators have a low kll rate, so could that have driven the T.rex's instincts to survive to become a scavenger?

Eye sight is vital for hunting. To keep track of the prey , without it escaping is ver important. By the time the T.rex had gotten any scent, would'nt the prey have escaped by the time it got to the preys location?

Jack Horner is just as good as Bob Barker. But we're not debating aboput them, are we?

There really is'nt any more to argue about, unless Mudboots has anything else to say?

[Saru]

It doesn't look like MIMB has anything else to add, so i'll consider this debate to be finished.

Thanks to both of you for taking part, now it's over to the judges.

[Falco Rex]

Okay; here we go:

Debator1: Man_in_Mudboots

Relavancy:8

Countering:7

Style:9

Persuasiveness:8

Total:32

Debator2: The Hunter

Relavancy:8

Countering:7

Style:5

Persuasiveness:7

Total:27

Congrats to you both. This one might have been too close to call but I had to deduct points from the style category from the Hunter for your constant self glorification. Tone it down a bit and you'll do really well here..

[reese2]

Here you go, the scores.....

Debator: Man_in_Mudboots

Relavancy:8

Countering:8

Style:9

Persuasiveness:7

Total:32

Debator: The Hunter

Relavancy:6

Countering:8

Style:6

Persuasiveness:7

Total:27

Good job to you both!!!

[BurnSide]

Very good gents. Here are my results:

Debator: Man_in_Mudboots

Relavancy:7

Countering:8

Style:8

Persuasiveness:7

Total:30

Debator: The Hunter

Relavancy:7

Countering:8

Style:7

Persuasiveness:6

Total:28

[Saru]

Thanks to the judges and to our participants.

The final results then show that Man_in_Mudboots has won this debate with a score of 31, while The_Hunter has scored slightly less with 27.