Tyrannosaurus rex: An Iconic Figure (Image Heavy Thread)

[andrewsaurus rex]

'fat' is not a good word, it was just a way of getting my point across in a tongue in cheek way.....I realize Rex wasn't fat.  But I do wonder about the current reconstructions. I don't have a problem with the width, more the depth.  I recognize the gastralium is wide, but I take some exception with how deep the chest and belly of Rex is now being portrayed.

The main justification for it is Rex's big bones.....the conclusion being they must have supported big muscles and hence Rex was big, deep and girthy.   But what that means is a lot of extra weight Rex had to carry around.  Most predators today are lean and muscular, not bulky and muscular.  The only bulky predators I can think of are bears and the are mostly omnivores.

When you are a predator, being heavy and bulky is a big problem.  It makes you slow, less agile and require a lot of extra food intake to maintain your bulk.

Rex's big thick bones could have served another purpose....to protect it from what was surely a very rough and tumble lifestyle.  Being a predator of large animals, Rex probably fell down a lot and faced enormous stresses on its body while tussling with prey.  Thick bones would offer protection from these falls and stresses.....lots of extra weight being carried would mean more severe injury form these falls.

Anyway, that's how I see it.  I'm probably wrong....I often am. 

[suspsy]

Your problem is that you're applying what you know about extant predatory land animals to one that's been extinct for 66 million years. I'm pretty sure I already pointed this out to you in the PNSO Wilson review. T. rex really isn't comparable to a tiger or a lion or a wolf or even a bear in terms of anatomy and physical ability. Similarly, the animals that it preyed upon are not comparable to deer or bovids. Triceratops, Ankylosaurus, and Edmontosaurus were all slower and less agile than T. rex, and dumber too.

Also, can you cite a reference for your argument about "big bones"? I've never seen such a thing proposed by any palaeontologist lately.

[andrewsaurus rex]

suspsy, we meet again....

I recognize they are extinct animals, but as I think I pointed out the Wilson review, the laws of physics were the same 66 mya as they are today.  And that means an animal that is lighter will usually be quicker and more agile than one that is heavy.  So, that being the case, T Rex's that were leaner and lighter would have had a competitive advantage over the ones that were big and heavy.  And able to be more successful at hunting.  In my view, selective pressures would have favoured this body plan over the big bulky Rex currently in vogue.

Let me be clear, Rex got big because his prey got big.....selective pressures made it the awesome animal it was.  But once it was big in stature (tall, long big head) there was no advantage to getting super bulked up.

Not only would a leaner Rex be better able to hunt, it would need less food than a bulky Rex.  So a bulky Rex now has 2 disadvantages: it is slower and less agile and it needs to eat more.  I think the leaner one would have the advantage in a survival of the fittest world.  And there is a third potential disadvantage for the bulky Rex.....he is probably more prone to serious injury when he falls.

In fact, I can't really think of any advantage the bulkier Rex would have, so I don't see it ever evolving.

The 'big bone big muscles' comments I've made I have read many, many times over the years regarding Rex.......can't quote a specific reference though, sorry and I honestly can't be bothered to look for one.  If you don't agree with me, fine.  I bet most on here won't.  But that doesn't change my mind.

[suspsy]

suspsy, we meet again....

I recognize they are extinct animals, but as I think I pointed out the Wilson review, the laws of physics were the same 66 mya as they are today.  And that means an animal that is lighter will usually be quicker and more agile than one that is heavy.  So, that being the case, T Rex's that were leaner and lighter would have had a competitive advantage over the ones that were big and heavy.  And able to be more successful at hunting.  In my view, selective pressures would have favoured this body plan over the big bulky Rex currently in vogue.

You're still trying to compare T. rex with modern predators, though. You're also erring in your assumption that evolution dictates that speed and agility must always take precedence over size and strength, which makes no sense regardless of the time period and the organisms. Going by your own argument, African lions can't possibly survive today because cheetahs and leopards and hunting dogs are all much faster and more agile. And yet they are the dominant predators in Africa, and they certainly don't rely on stealing or scavenging the kills of those other predators.

Let me be clear, Rex got big because his prey got big.....selective pressures made it the awesome animal it was.  But once it was big in stature (tall, long big head) there was no advantage to getting super bulked up.

These statements contradict one another. If T. rex got bigger because its prey got bigger, then there absolutely is a potential advantage to being even bigger still. But you also appear to be assuming that the size of a predator is determined primarily by what it feeds on without considering that there could be other evolutionary advantages. Such as attracting mates or holding on to territory.

Not only would a leaner Rex be better able to hunt, it would need less food than a bulky Rex.

Leaner carnivores do not automatically consume less food than larger ones. On the contrary, they often consume more due to their metabolisms.

And there is a third potential disadvantage for the bulky Rex.....he is probably more prone to serious injury when he falls.

Incorrect again, I'm afraid. A 5 ton T. rex would be just as prone to serious injury from a fall as a 10 ton one.

In fact, I can't really think of any advantage the bulkier Rex would have, so I don't see it ever evolving.

What exactly do you mean by "ever evolving"?

The 'big bone big muscles' comments I've made I have read many, many times over the years regarding Rex.......can't quote a specific reference though, sorry and I honestly can't be bothered to look for one.  If you don't agree with me, fine.  I bet most on here won't.  But that doesn't change my mind.

If you can't or won't share supporting evidence, then frankly, there's no point in continuing this discussion any further. Needless to say, the current restoration of Tyrannosaurus rex has been built on the foundation of years of research carried out by multiple experts, including Thomas Carr, Thomas Holtz, Stephen Brusatte, and Scott Persons to name a few. It could well change again in the face of new evidence and new research, but until that comes to pass, the bulky restoration is the correct one. Regardless of whether or not it "feels right" to you.

[Halichoeres]

I only keep figures showing the most up to date appearance of each extinct animal in my collection.  The others get sold, stored away carefully or used for spare parts in any custom work I do.

This is similar to my approach to collecting, too. But at this point the surfeit of Tyrannosaurus figures means that any improvements offered by new figures are so minor that it would take a lot to make me buy one. The same is true for Spinosaurus, Giganotosaurus, Carnotaurus, and soon will be true for Carcharodontosaurus.

[andrewsaurus rex]

ok suspsy:

i'll respond once more on tis issue and then we're going to have to agree to disagree.  I'm sorry that i'm not just blindly following what people tell me, even if those people are experts.  Experts make mistakes too.  Have they in this case?  Doubtful.  But the fact that it doesn't 'feel right to me' is going to be what I go by, for ME.   I'm not asking one other person on the planet to agree with me.

Now to your post:

I wasn't comparing T Rex to smaller more agile predators.  I was comparing Rex to other Rex's.  And your analogy with lions will help illustrate my point.  Male lions generally have difficulty hunting for prey....and the bigger the male, the more difficult it is.  This seems illogical but the problem is the bigger the males get, the slower they run.  They are super powerful and if they can catch prey the can dispatch it with ease but the problem is they have trouble catching it.  Not only because they are slow, but because their large size and big manes make them easier to spot from a distance, making it difficult for them to get close enough to prey to ambush them.  It is not uncommon for large male lions to starve to death, if they lose their pride of female lions to a rival male.  The females do the hunting and the large males protect the female's cubs from other large male lions....that is the male's primary job.  So, if T Rex had a system like this than I would totally agree that SOME Rex's were big and bulky, because in that scenario, mass and bulk is very advantageous....not for hunting but for battling other large members of their own species.  It is the leaner, faster more agile female lions that are the good hunters.

As to your second point: my statements don't contradict......Rex got big because their prey got big, but once they were big enough to deal with the larger prey getting bulkier and heavier would not only not give further advantage, it would start to be disadvantageous, for the reasons I've stated (slow, less agile, needing more food etc).

A larger Rex would most certainly require more food to maintain it's bulk than a leaner Rex....just the same way a 250 pound man needs more food to stay at 250 pounds than a 180 pound man needs to consume to stay at 180.  In most cases.  Sure there may be the odd exception where metabolisms would make a difference, to a degree.   But within any species normally, bigger members of the species will need more food than smaller members of the species.

A 10 ton Rex would be more prone to injury form a fall then a 5 ton Rex because the force of impact from the fall would have much higher kinetic energy.  It wouldn't result in twice the injury but it would mean it is at greater risk of injury from the fall, due to the higher impact forces because of its bulk.  This point was a minor one, anyway...my two main points were slower and less agile and needing more food to maintain bulk.   

re: 'ever evolving'.....my statement was: "In fact, I can't really think of any advantage the bulkier Rex would have, so I don't see it ever evolving".  I'll state it another way to clarify my point.  I can't really think of any advantage the bulkier Rex would have over a leaner Rex, so I don't see how there would ever be selective pressures to cause T Rex to evolve into a bulkier, heavier, slower animal.  Note: However, if we use the male lion analogy I could easily see that a small number of Rex's may get big and bulky, assuming their job was protection of a 'pride' and not hunting.

I'm surprised I am needed to share supporting evidence for my assertion that T Rex had large robust big bones that were attachment points for large muscles.  That has been stated many, many times over the decades since Rex was discovered.

Anyway, i'm not here to change anybody's mind on this subject, and as I said in one of my posts above, I may well be wrong.  But if something just doesn't feel right to me I have trouble just blindly accepting it, even if it is the opinion of experts.  It's not like I disagree with everything I learn, but from time to time, I just can't buy into certain ideas that are proposed.  For Rex, I can accept that SOME members of T Rex were big and bulky, like big male lions but not that all members of T Rex were big and bulky.

[Dusty Wren]

Male lions generally have difficulty hunting for prey....and the bigger the male, the more difficult it is.  This seems illogical but the problem is the bigger the males get, the slower they run.  They are super powerful and if they can catch prey the can dispatch it with ease but the problem is they have trouble catching it.  Not only because they are slow, but because their large size and big manes make them easier to spot from a distance, making it difficult for them to get close enough to prey to ambush them.  It is not uncommon for large male lions to starve to death, if they lose their pride of female lions to a rival male.  The females do the hunting and the large males protect the female's cubs from other large male lions....that is the male's primary job. 

I don't understand this statement at all. Male lions definitely hunt. And they're as good at it as females; there are studies that show that sex has no effect of the probability of a successful hunt.

Males may hunt different types of prey than females, but males can spend years living in small bachelor groups and they don't starve. This isn't a good analogy if you're arguing for a leaner body type for T. rex.

[suspsy]

ok suspsy:

i'll respond once more on tis issue and then we're going to have to agree to disagree.  I'm sorry that i'm not just blindly following what people tell me, even if those people are experts.  Experts make mistakes too.  Have they in this case?  Doubtful.  But the fact that it doesn't 'feel right to me' is going to be what I go by, for ME.   I'm not asking one other person on the planet to agree with me.

This is an argument from personal incredulity, meaning it's not a valid argument at all. Science does not and cannot rely upon faith; it has always relied on the carrying out of research, the sharing of that research, and the debunking or validating of that research. You might as well be arguing that you refuse to accept the science behind evolution or climate change or vaccines because it "doesn't feel right to you."

Also, who's telling you to blindly accept the words of the experts? Have you bothered to read their words in the first place? For example, have you read this recent paper on the growth stages of T. rex by Thomas Carr? He's devoted practically his entire paleontological career toward studying the tyrant king. Very informative read.

https://peerj.com/articles/9192/?utm_source=BlogPost&utm_medium=organic&utm_campaign=T-Rex&utm_term=PeerJ&utm_content=Interview

@Dusty Wren already pointed out that male lions are perfectly capable of bringing down live prey on their own. So are male tigers, which are even heavier. And male polar bears, which are more than twice as heavy as any lion or tiger. And you still do not seem to be taking into account that the kind of animals T. rex preyed on grew to be just as heavy or heavier than even Sue or Scotty. And slower and dumber, as I already pointed out. 

A larger Rex would most certainly require more food to maintain it's bulk than a leaner Rex....just the same way a 250 pound man needs more food to stay at 250 pounds than a 180 pound man needs to consume to stay at 180.

. . . I'm sorry, but that makes no sense. That's not how the human body works. Especially given that you're not taking lifestyle into account.

A 10 ton Rex would be more prone to injury form a fall then a 5 ton Rex because the force of impact from the fall would have much higher kinetic energy.  It wouldn't result in twice the injury but it would mean it is at greater risk of injury from the fall, due to the higher impact forces because of its bulk.

This is also not in keeping with the research that has been carried out.

re: 'ever evolving'.....my statement was: "In fact, I can't really think of any advantage the bulkier Rex would have, so I don't see it ever evolving".  I'll state it another way to clarify my point.  I can't really think of any advantage the bulkier Rex would have over a leaner Rex, so I don't see how there would ever be selective pressures to cause T Rex to evolve into a bulkier, heavier, slower animal. Note: However, if we use the male lion analogy I could easily see that a small number of Rex's may get big and bulky, assuming their job was protection of a 'pride' and not hunting.

Modern bears do not live in prides, nor do they protect one another save for mothers with cubs. And yet the largest bears definitely enjoy a number of advantages from their size. Mature bull elephants live alone, and do not protect any other elephants from danger, yet the largest ones enjoy similar advantages. I could go on for a long time.

I'm surprised I am needed to share supporting evidence for my assertion that T Rex had large robust big bones that were attachment points for large muscles.  That has been stated many, many times over the decades since Rex was discovered.

Large muscles do not necessitate that an animal has to be lean, which appears to be the basis of your opposition to the current restoration. And you should not be surprised when someone asks you for supporting evidence in a scientific debate. On the contrary, you should expect it.

I strongly urge you to read Carr's paper, and also the one by Scott Persons officially describing the Scotty specimen.

[Bread]

With the addition of the gastralia for Tyrannosaurus, this heavy build of this genus is probably the definitive reconstruction. I actually feel as a slimmer, not as bulky Tyrannosaurus would have more disadvantages compared to a bulky, heavy set Tyrannosaurus. With being a lighter build, the Tyrannosaurus could not substantiate injuries from armored prey. I understand the thought of a heavier Tyrannosaurus not being able to catch an Edmontosaurus, however it was not their primary diet, nor do I think any genus was their primary diet. Like any predator, opportunistic prey is a thing.

[Flaffy]

i'll respond once more on tis issue and then we're going to have to agree to disagree.  I'm sorry that i'm not just blindly following what people tell me, even if those people are experts.  Experts make mistakes too.  Have they in this case?  Doubtful.  But the fact that it doesn't 'feel right to me' is going to be what I go by, for ME.   I'm not asking one other person on the planet to agree with me.

So basically you're admitting to blatantly ignoring decades of research and science in favour of a personal hunch?

As Suspsy has said, when engaging in scientific discussions, be prepared to prove scientific evidence for your claims. And mind you, you are making some very extraordinary claims. "just look at xyz creature" or "it's just common sense" is not nearly sufficient to make your argument convincing.

I also feel like you're either missing, or ignoring a massive part of the picture: The morphology of Tyrannosaurus's prey.
There's a reason why ceratopsians grew larger and larger over the course of their evolution, and Tyrannosaurs were (one of) the driving forces for that. There's no reason to assume that the evolutionary arms race between tyrannosaurs and ceratopsians was over by the time of Tyrannosaurus. As ceratopsians became more adapted at fending off their predators, then selective pressures would favour tyrannosaurs better equipt at dealing with increasingly large and defensive prey. It's no coincidence that Chasmosaurs went from having thin crests with large openings; to having (comparatively) dense and thick crests with small to no openings as seen later members of Triceratopsini. The significant increase in size and mass of Triceratops compared to other chasmosaurs is definitely a driving force for Tyrannosaurus to adapt as well.

So what did Tyrannosaurus have to regularly deal with?
- Two to three of the largest Ceratopsids to ever exist
- Two of the largest Ankylosaurs to ever exist
- One of the largest Hadrosaurs to ever exist
and if Tyrannosaurus ever fancied a travel down South, it'd be faced with a very modestly sized Titanosaur.

I don't see how anyone can argue that a larger, bulkier Tyrannosaurus would be facing any significant disadvantages given it's massive, slow and/or highly defensive contemporaries.


As for speed, that's a whole other can of worms. Tyrannosaurids have many adaptations (especially in their leg bones) for speed, agility and endurance, and this would've certainly carried over to Tyrannosaurus itself. Long story short, Tyrannosaurus certainly would've been able to utilise these adaptations in its favour. Even then, the heavily armoured Ceratopsians and Ankylosaurs of HC were certainly not known for their speed. Tyrannosaurus only had to be fast enough to catch up to it's prey.

[Flaffy]

-deleted-

[andrewsaurus rex]

at about age 2 young male lions are kicked out of their pride by the male in charge.  At that point they will hunt solo or in bands of brothers.  They can be successful at this point because they are smaller and can stalk and ambush prey more easily without being spotted.  Their smaller size means they are as fast as female lions as well.

But once they attain their full adult size, if they haven't found a pride they are in trouble because their huge size makes it difficult for them to sneak up on prey and unless the prey is injured or sick, they are too slow to catch them.  Male lions will join sometimes when the females hunt, but they are there as muscle to do the killing.  The smaller faster females do the stalking and catching.

Even larger females are often too slow to catch prey.  When females hunt in groups the smaller females will stalk and chase the prey and dive it to where the larger females are waiting.  It is the larger females' job to do the killing.

Fortunately for the large males their size gives them a fighting chance (literally) of being able to get their own pride.....either by taking over an existing one or by attracting stray females they encounter.

Since only about 1 in 8 male lions reach adulthood, there is a surplus of females around, allowing most large adult male lions to find a pride.

[andrewsaurus rex]

ok gang.....getting a bit tired of some of the attitudes on here.

I will state my opinion if I want.  I will disagree with decades of research by experts and go with personal hunch if I want.

Not sure why some of you seem to be taking this personally.

[Bread]

I will state my opinion if I want.  I will disagree with decades of research by experts and go with personal hunch if I want.

Not sure why some of you seem to be taking this personally.

That's 100% fine. However, I feel like you should have addressed the disagreement with research a few posts ago. I believe that's why the argument continued.

[suspsy]

ok gang.....getting a bit tired of some of the attitudes on here.

I will state my opinion if I want.  I will disagree with decades of research by experts and go with personal hunch if I want.

Not sure why some of you seem to be taking this personally.

Pretty sure nobody who has responded to your arguments here is taking any of it personally. At most, we are puzzled by how you refuse to acknowledge the shortcomings in them. Did you read Thomas Carr's paper yet? Or either of those ones on lions? Heck, one needs only to check YouTube to see that male lions aren't as inept at hunting as once thought!

https://youtu.be/o-yhrTnblPE

You are 100% free to continue disagreeing with the paleontological community if you wish, but that's like disagreeing with the medical community over face masks. The science behind them is solid and so is the science behind the robust restoration of Tyrannosaurus rex.