T.rex: Hunter or scavenger?

Saruman

OK here is a question and a valid one. I don't have an answer and im swayed both ways as to the answer... Its fun though when you think about it and if you saw any of the Documentaries on Discovery about this then you will be as informed as I am.

Btw if there are any Palaeontologists or anyone who thinks they know what they are talking about with Dinosaurs I don't want the typical answer their profession dishes out because its what's generally accepted... if you state and opinion I want to know why and also what makes you think the other one is wrong.

So was T-Rex the largest or at least one of the largest known predators in the history of the earth? They lived near the end of the Cretaceous period 65 million years ago so what do you think? Most people see them that way.. of course they are huge with big teeth etc.. they have to be predators... OR do they?

Lets look at some obvious facts! Their tiny little forelimbs for one! All biped Predators of that era had larger forelimbs for grappling with prey, even predators as big or bigger than the T-Rex like Spinosaurus (the one in Jurassic Park 3!). Secondly like in the Giraffe jumping thread.. what happens when T-rex is running down its prey and oops it trips and falls.. it would not only do serious damage to itself considering its size.. but with no forelimbs it would be a difficult task to get up! Does not seem like even if they were predators that they could be successful considering this.. they lived for millions of years so they were obviously successful. And the one I find the most interesting is their teeth, they had the largest teeth I think known to exist. The animals that have the largest and sharpest teeth these days are scavengers like Hyenas and so on.. also like Hyenas and vultures and other scavengers... the T-Rex looks menacing.. its huge, huge teeth, big snout probably even had bright colour pigmentation on the face like a vulture!! what better way to scare predators away from a kill and steal it! And also its sense of smell.. it had one of the best sensory systems for smell.. like most scavengers who need to detect dead or dying animals over long distances.. also its eyesight is supposedly bad.. completely unlike any predator today...

Maybe its a mixture of both... an opportunist like the Hyena.. scavenges but when it has the opportunity it becomes a predator!

Lets hear opinions here!

Rafter

could'nt give a flying F*%* eitherway!!!:D

Saruman

could'nt give a flying F*%* eitherway!!!

Scavenger or Predetor im sure it would eat you Rafter

EvilGeorge

Fair enough , I see your point, well what ever it had to do was obviously for survival which I'm sure is the primary instinct of any species (except for the dodo), so I would go for a mixture really (but you did have pleb in the pole so my vote actually went there!!).

scipio_major

I think the T-Rex was probabally a bit of both. Considering the way things are amount modern (since we humans were able to record) predators I can't think of a single canivore which would do both. I've watch National Geographic documentaries where the noble lion has scavaged the hyena's kill. Basically if we assume that the T-Rex lived in a time where there was a limited supply of food, it would be damn glad to get food where ever it found it.

On the little forearms front, I don't think you can claim that it couldn't have been a predator on that basis. True a lot of dino predators had big forearms but not all had such huge jaws. Crocodiles don't have big forearms and they get on just grand. As for falling over I point to the kangaroo, T-Rex also had a big tail for balance so I doubt it could it would trip all that often.

Fade to Credits
Scipio_major

P.S Suraman, what has set off this bombard of polls?

Saruman

Could be a bit of both.... I think so but most animals have a primary means of survival... a Lion will scavenge if it needs to but primarily hunts just like a Hyena (which in case people are interested is not a type of Dog! Its related to the cat and the mongoose more than the Dog). Anyway a Hyena scavenges mostly but will act the predator when they get a chance.

Humans even are Predators, the most successful ever but we can also be scavengers if the need arrives... So while yes a bit of both goes for T-Rex im more interested in its primary method of survival. Another thing is a T-Rex is a huge animal and I doubt is very stealthy so the only way I can think it could have worked as a Predator would be ambush. Hide in a bush and then pounce when something walks by! I cant see it creeping up on another Dinosaur easily.

Crocodiles don't have big forearms and they get on just grand.

Not the same! A croc is a completely different type of creature.. firstly they are amazingly stealthy.. they are masters of it! And secondly they dont need to grapple as they spin around and so tear the flesh right off their prey.. a T-Rex cant do anything of the sort!

As for falling over I point to the kangaroo, T-Rex also had a big tail for balance so I doubt it could it would trip all that often.

Maybe true but then a roo does not weigh in the Tonnes and also their forelimbs are quite long.. long enough to have boxing matches with each other during mating season! Plus they are not predators! Their survival is not at stake in the same way if they fall.. if they do they get up unless they are the prey and they don't have many predators!! T-Rex though cant afford to fall during a chase! It will loose its prey if it is in fact a predator. Now here is something interesting! Older T-Rexes say had longer forelimbs etc.. they also had longer leg bones which means they could run faster! Newer T-Rexes of the kind we tend to find the most examples of had shorter leg bones and shorter forelimbs indicating that T-Rex may have once been a predator but was evolving into a scavenger.. maybe as a result of changing environment and its prey dieing off so out of necessity it became more scavenger.. remember the T-Rex was around near the end of the reign of the Dinosaurs so while many believe an impact killed off the Dinosaurs, many also believe it was happening because of climate change anyway and they were in decline.

any more thoughts?

P.S Suraman, what has set off this bombard of polls?

scipio_major the easy answer... boredom! nothing better to do its either this or do some work!!

Terminator

Yes if the T-rex slips it will be difficult to get back up and the hunt is over. But most predators have a low success rate anyway.

Just look at the cheetah chasing the antelope - 9 times out of ten the antelope gets away to fight another day.

Cerberus

I've had an interest in dinosaurs since a very young age and have seen this debate a few times.
My own personal opinion based on what I have seen and read is this.

The T-Rex was a reptile. The ancestors of present day crocodies, turtles and lizards. I don't agree with the statement that dinosaurs were birds. They are more likely to be a seperate branch off from a previous ancestor. It is logical to assume that life first learned to walk before it learned to fly.
Most reptiles will eat anything. They have the most acidic stomachs of any creature and their digestive systems can take anything...bones, rocks, skins, hoofs, very few bacteria known to have any affect on them. This enables them to be both scavenger and predator. They are oppurtunistic. Whatever they find they eat - dead or alive. The T-Rex would have been no different( that said, I have seen at least one docu saying they had very fragile stomachs although I would reckon in that era no carnivore had a fragile stomach.) When times are good eat - fresh meat and take only the choiciest bits . When prey is scarce, scavenge smaller kills made by more agile creatures . I don't think the fact that the T-Rex had small forearms had any affect on its ability to take down its prey. Those teeth!! It would not be necessary to take down the prey all at once. One bite would do a lot of damage to most animals of that day even brachiosaurus, brontosaurus and diploducus(although this would be a last ditch attempt at getting food - it'd be like fcuking with the bouncers). Injure the animal and wait for it to slowly weaken then move in for the kill. 12 inch teeth on an animal that big would have dealt a devasting blow. The T-Rex was also one of the fastest dinosaurs so it didn't need to rely that much on stealth. It is also possible that they hunted in packs on occassion although I'm not convinced on that part. I've seen conflicting reports. There would be no problem with the T-Rex getting up after a fall either - the tail was more than sufficent for righting itself. Anyways thats my 2 cents(cent?). Im not saying anything in here is proven fact. As I said at the start, there is lots of conflicting reports out there. A lot of them state opinion without saying that they are doing so. Different paleonthologists would have different ideas and would make docus to suit their own opinions without telling the watcher that they are. That said - Walking with Dinosaurs - spectacular. I must get the video colection of the series and the new one walking with beasts.

Saruman

I think Cerberus that short of traveling back in time (not likely) or doing Jurassic park for real and cloning them.. we will never know for sure.. Unless we found a perfectly preserved feeding ground complete with dinos frozen in ice or something!

Wouldnt even call it a scavanger,i would say it was a hunter .This Theory of it falling over and not getting up is a little stupid i think .Just because it has small limbs .Look at a bird.I have seen birds that have had their wings clipped ,fall over and easily get back up,and that is with no limbs atall .I know the T Rex is larger but i bet you if one was to fall over i could get back up with no hassel. Mabey it was both a scavanger and a hunter .

Cerberus

Jesus...I don't remember writing any of that. I was at the end of 2 all nighters in a row for a FYP interim report.
Hold the thought on that travelling back in time though. I am currently working on a way of opening up a temporal rift in space time using a condom and a pack of Jaffa cakes(the ordinary ones - not the all-chocolate covered ones cos I don't like them).

Anyways, yeah tis an interesting aul subject and more relevant to modern day than most people would think. Whatever event happened that more or less annihilated the most successful animals ever to roam the earth should always be very relevant to us.

Saruman

Absolutly Cerberus!

the omen

Im not sure if its all that true but some scientists believe that the purpose for the small arms was to make it easier to grapple long necked herbivores mainly like the brontasaurus or the brachasaurus which were believed to be the main part of the T-rex's diet.They suppositly used there powerful jaws as there main weapon (makes sense!).As whether it was a predator or scavenger well i think they wouldnt have cared where the food came from and scavenging is alot less tiresome than hunting.

Captain Janway

If i were built like a Trex i would not lower myslef to scavenge. Why would they need to? this animal feared nothing. It could be attacked sure enough, but the attacker would need to be one savy animal, part of a large pack, or the Trex would have to injured.
They probably did scavange, but not in the normal sense,they could be wondering along minding their own business , maybe thinking about that femaleTrex(there is a question : what is a female Trex called) they had the other night. and next thing you know they come accorss these tiny little dinosaurs who have just killed some kind of snack like animal. The Trex would think(I'll have that). After all who is going to stop him.

Also Is there any documented proof that Trexes ran in herds. I think that most scavangers run around in herds.

the omen

what is a female Trex called

Ah Mrs.T-Rex

azezil

Possibly both, but i'd consider that becuase of its short front limbs it'd make it harder for it to scavenge?

Saruman

Originally posted by azezil
Possibly both, but i'd consider that becuase of its short front limbs it'd make it harder for it to scavenge?

Would not matter at all, I doubt many predetors used their forlimbs when eating.. just like birds! They bite into the carcass as hold it with their fut then tear it off..

As for the Birds/Dinosaurs Debate.. The beginings of birds can absolutly be traced back to Dinosaurs... both in skeletal terms and Genetically! There were no birds in the time of the Dinosaurs, but near the end dinosaurs with feathers appeared and later still more that looked more like birds with a beak instead of snout and so on. ending up in birds and then breaking off into all the subspecies! Its not a case that each bird type was once a type of dinosaur i.e Eagles were Raptors, Condors were T-rex etc.. thats crap if its what you think.. In fact there is no proof that a lot of dinosaurs did not grow feathers! Its logical to assume that the leftover dinosaurs if it was Cold that cilled them or a meteor.. same effect it gets cold.. a metoor would have blocked a lot of sunlight from the debris in the atmostphere and the volcanic activity that probably followed so it would have got colder and as a defence, dinosaurs would have grown pretection.. i.e feathers!

TomF

Whenever I hear about this dinosaur, I call him:
Tyranosaurus R.

Saruman

Originally posted by TomF
Whenever I hear about this dinosaur, I call him:
Tyranosaurus R.

Thats inspirational to know!

Cerberus

If you think that name is annoying then then what about Manospondylus gigas? Thats what the T-Rex probably should have been called. The first skeloton was found in South Dakota in the 1900s. The dude that found it called it Manospondylus gigas. But he didn't find the full skeleton and then other dudes found another skelton and called it Tyrannosaurus Rex (giant lizard king). Later when they found the rest of the Manospondylus gigas in South Dakota they realized it was the same animal as the T-Rex. I don't think Jurassic Park would have been as popular if the main bad ass was called Manospondylus gigas.

scipio_major

Out of total curiousity what does Manospondylus gigas mean?

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Scipio_major

Saruman

It was the guys name!

Cerberus

A not so quick search of google turned up this
"giant, thin vertabrate"

TomF

Oops, I meant Tyrannosaurus R.

I was born in South Dakota.

Bob the Unlucky Octopus

Evidence T. Rex was a hunter: Outdated paleontological theory + Jurassic Park

Evidence it was a scavenger: Recent paleontoligical evidence + theory.

Occy

Galvasean

In case anyone's wondering this is a merge of the Popular Science thread and the one in Palaeontology. (hence why the thread actually predates the Palaeontology Forum - it's here for archiving reasons)

So back on topic:
Could it be true that like Dr. Jack Horner states in his documentary Valley of the T.Rex.
An article summing up his position can be read here.

And an interesting rebuttal can be found here.

So anyone got any thoughts/opinions on the matter either way?

AtomicHorror

The arguments for "scavenger" sound quite compelling... I'd much rather imagine the T. rex as a hunter though

Galvasean

AtomicHorror wrote: »

The arguments for "scavenger" sound quite compelling...

Indeed they do... until you start reading the rebuttals, most of which are outlined in the link above. However they forgot to mention that before Dr. Horner published his findings (on TV no less!) conclusive evidence that Tyrannosaurus hunted at least on occasion. So far both Triceratops and Edmontosaurus bones have been discovered with Tyrannosaurus tooth marks in them which have actually healed. Of course wounds only heal when the creature in question survives the attack. This proves beyond a shadow of a doubt that Tyrannosaurus did hunt at least from time to time and, like all predators, did not always successfully make a kill. Putting to rest Horner's "one hundred percent scavenger" to rest.
I'm not saying T.rex was a complete predator either, merely that like pretty much every carnivore it was a mixture of both.

animan

I think scavenger. If it did hunt I don't imagine it could run very fast.

Galvasean

animan wrote: »

I think scavenger. If it did hunt I don't imagine it could run very fast.

Recent analysis suggests it ran at 18 miles per hour. That's faster than people.
http://www.eurekalert.org/pub_releases/2007-08/uom-trq082107.php

lifeisawarfield

The T.Rex, as proven on many documentries, is a slow reptile, iits forelegs are to small and there fore, when falling over, could not pick itself up again. The T.Rex hunted, yes, BUT only when it knew there was easy prey about, OR it ambushed. Otherwise the T.Rex was a scavanger, and, given its size, would easly get a meal of of small, more capable hunters, such as the velocirapter, which is thought to have hunted in packs.

And therefore i concluded my answer as, the T.Rex was both.

dlofnep

I would say that he was both. Also, the younger t-rexes seemed to have longer legs than the parents.. Perhaps suggesting they were used to chase prey towards the larger parent, who could then finish the job. I would imagine a T-rex family worked together as a single unit in a small pack. It was IMO a hunter first, scavenger second.

lifeisawarfield

Yes. T.rex skeletons have been found together, younger and older, thought to be family, mother and children. And yes, the young do have longer legs, so maybe they did hunt, and the adults finish the job, but until we find evidence, we will just have to believe what we think is right =].;):rolleyes::cool:

Galvasean

lifeisawarfield wrote: »

Otherwise the T.Rex was a scavanger, and, given its size, would easly get a meal of of small, more capable hunters, such as the velocirapter, which is thought to have hunted in packs.

Seems like a waste of energy for T.rex to travel all the way over to Mongolia to steal Velociraptor's dinner.

lifeisawarfield

guh... Yeah, i am stupid, brain was numb, O.o why do i not sleep.... Sorry, i was just using an example.:eek:

AtomicHorror

lifeisawarfield wrote: »

The T.Rex, as proven on many documentries...

Let me just stop you there... documentaries are the second last place you look for proof of anything. The very last is tabloid newspapers.

Galvasean

AtomicHorror wrote: »

Let me just stop you there... documentaries are the second last place you look for proof of anything. The very last is tabloid newspapers.

Hence my problem with the documentary 'Valley of the T.rex' with its one sided message of "OMFG T.rex was a complete scavenger!!!" when earlier research (which was subsequently ignored for the sake of shock value to sell the documentary) indicated that it was capable of hunting.

housemap

Terminator wrote: »

Just look at the cheetah chasing the antelope - 9 times out of ten the antelope gets away to fight another day.

The cheetah is one of the most successful predators on earth and by far the most successful cat - 50% of chases result in a kill.

Galvasean

Well, looks like it was virtually impossible for T. rex to get the fuel it needed from scavenging alone:
http://blogs.smithsonianmag.com/dinosaur/2011/01/for-t-rex-scavenging-was-a-tough-gig/

scottie pippen

In my opinion, T rex was a hunter/scavenger, would be ridiculous to think that any predator would pass a free meal.

scottie pippen

who did Did T-Rex compete with for food?

or depending on what you believe - who was the top predator making the kills in the same region as T-Rex.

& who did T-Rex compete for carrion?

Galvasean

Of the top of my head...
As far as 'proper' (excluding small insect hunters) carnivores go the habitat contained:
Dromaeosaurus
Troodon
Chirostenotes (or something very like it, a medium-large relative of Oviraptor
Nanotyrannus (assuming it was distinct from Tyrannosaurus

(I'm just gonna merge this thread with the scavenger debate thread. The forum is getting fairly tyrannosaur heavy)

Gunsfortoys

People have to look at this objectively, the dinosaurs that the rex would have hunted were all very slow movers in comparison to it.

I mean it would take one lethal bite to the spine of a huge herbivore to incapacitate it, then the rex would simply watch as it bled to death.

Galvasean

Gunsfortoys wrote: »

People have to look at this objectively, the dinosaurs that the rex would have hunted were all very slow movers in comparison to it.

I mean it would take one lethal bite to the spine of a huge herbivore to incapacitate it, then the rex would simply watch as it bled to death.

While you are indeed correct about the incapacitating bite (T. rex's jaws could crack through bone), the dinosaurs of the time were apparently much faster than once thought - particularly the seemingly defenseless hadrosaurs.

T. rex apparently was too.

PS: Hello and welcome to the forum!

scottie pippen

Its possible that a T-rex could ambush its prey, hide among some trees & spring out as they pass by. if it took an animal by surprise,
it might not have to run too far, just a short burst of speed, Aligators and Crocs are like this - short fast powerful burst of energy but they get tired quickly. The shape of Tyrannosaurs skull indiates their brain was similar in shape to a Croc's brain - its possible they might hunt like this & scavenge when they can

Galvasean

scottie pippen wrote: »

Its possible that a T-rex could ambush its prey, hide among some trees & spring out as they pass by. if it took an animal by surprise,
it might not have to run too far, just a short burst of speed, Aligators and Crocs are like this - short fast powerful burst of energy but they get tired quickly. The shape of Tyrannosaurs skull indiates their brain was similar in shape to a Croc's brain - its possible they might hunt like this & scavenge when they can

I'm pretty sure that's the general consensus alright. If that link I posted in my last post is anything to go by (it's endorsed by the top tyrannosaur experts so I'd say it's quite sound) it would be capable of a very fast dash, but it was certainly no marathon runner. In fact, the conclusion is basically what you've said in your post there. Good summary sir.

Gunsfortoys

scottie pippen wrote: »

Its possible that a T-rex could ambush its prey, hide among some trees & spring out as they pass by. if it took an animal by surprise,
it might not have to run too far, just a short burst of speed, Aligators and Crocs are like this - short fast powerful burst of energy but they get tired quickly. The shape of Tyrannosaurs skull indiates their brain was similar in shape to a Croc's brain - its possible they might hunt like this & scavenge when they can

Hmm maybe.

If indeed the T.rex is more of a plodding animal as per the article above, that means it would have been crouched quite a lot. This proves the theory that it could have been a stealth hunter, this coupled with the T.rexs' short arms further the ideas that it could have been a hunter as well as scavenger whenever situation dictates.

gbee

As I'm not a palaeontologist, I rely on Discovery channel for my information.

If they say T Rex is a fierce hunter, I believe them.

If they later say T Rex was a bird like creature who scavenged, then I believe them.

If they say that T Rex was probably a lazy hunter and could only catch snacks, but scared away packs of smaller predators who had brought down a big meal and he'd steal it, I'd believe them.

Gunsfortoys

gbee wrote: »

As I'm not a palaeontologist, I rely on Discovery channel for my information.

If they say T Rex is a fierce hunter, I believe them.

If they later say T Rex was a bird like creature who scavenged, then I believe them.

If they say that T Rex was probably a lazy hunter and could only catch snacks, but scared away packs of smaller predators who had brought down a big meal and he'd steal it, I'd believe them.

Discovery be thy god. :pac:

scottie pippen

gbee wrote: »

As I'm not a palaeontologist, I rely on Discovery channel for my information.

If they say T Rex is a fierce hunter, I believe them.

If they later say T Rex was a bird like creature who scavenged, then I believe them.

If they say that T Rex was probably a lazy hunter and could only catch snacks, but scared away packs of smaller predators who had brought down a big meal and he'd steal it, I'd believe them.

but would you believe a movie if they said its Vision was based on movement?

Galvasean

scottie pippen wrote: »

but would you believe a movie if they said its Vision was based on movement?

I love the part in the novel of The Lost World where they reveal that the 'vision based on movement' idea is incorrect. Turns out the T. rex could see just fine. It just hadn't yet identified Grant et all as prey yet.

I'm going to quote Jack Horner (making a pact with the devil?):
"Even if he couldn't see ya, he could sure as hell smell ya!"