Hello! Apologies if questions about scavenging T-Rexes have been asked to death…

First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?

Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?

Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…

On Tuesday, September 5, 2023 at 9:08:44 AM UTC-7, Sight Reader wrote:
> Hello! Apologies if questions about scavenging T-Rexes have been asked to death…
>
> First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?
>
> Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?
>
> Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…
Most predators don't turn their noses up at eating free meals. That said, the idea of short arms for "defending" corpses is ridiculous.

Lol… their arms are ridiculous too! I suppose, when it comes to explaining those tiny arms, one must “get used to disappointment”, as the Dread Pirate Roberts said…

As to T-rex being primarily a scavenger, it sounds like that theory has pretty much died…

On Tuesday, September 12, 2023 at 9:03:28 AM UTC-6, erik simpson wrote:
> On Tuesday, September 5, 2023 at 9:08:44 AM UTC-7, Sight Reader wrote:
> > Hello! Apologies if questions about scavenging T-Rexes have been asked to death…
> >
> > First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?
> >
> > Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?
> >
> > Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…
> Most predators don't turn their noses up at eating free meals. That said, the idea of short arms for "defending" corpses is ridiculous.

On 9/13/23 6:37 AM, Sight Reader wrote:
> Lol… their arms are ridiculous too! I suppose, when it comes to explaining those tiny arms, one must “get used to disappointment”, as the Dread Pirate Roberts said…
>
> As to T-rex being primarily a scavenger, it sounds like that theory has pretty much died…
>
> On Tuesday, September 12, 2023 at 9:03:28 AM UTC-6, erik simpson wrote:
>> On Tuesday, September 5, 2023 at 9:08:44 AM UTC-7, Sight Reader wrote:
>>> Hello! Apologies if questions about scavenging T-Rexes have been asked to death…
>>>
>>> First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?
>>>
>>> Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?
>>>
>>> Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…
>> Most predators don't turn their noses up at eating free meals. That said, the idea of short arms for "defending" corpses is ridiculous.

Some predators, notably lions an hyenas, take kills away from other
predators, and this may form a fair fraction of their diets. Whether T.
rex ever did such a thing is unclear, and I see no way of finding out.

On Wednesday, September 13, 2023 at 8:01:13 AM UTC-6, John Harshman wrote:
> On 9/13/23 6:37 AM, Sight Reader wrote:
> > Lol… their arms are ridiculous too! I suppose, when it comes to explaining those tiny arms, one must “get used to disappointment”, as the Dread Pirate Roberts said…
> >
> > As to T-rex being primarily a scavenger, it sounds like that theory has pretty much died…
> >
> > On Tuesday, September 12, 2023 at 9:03:28 AM UTC-6, erik simpson wrote:
> >> On Tuesday, September 5, 2023 at 9:08:44 AM UTC-7, Sight Reader wrote:
> >>> Hello! Apologies if questions about scavenging T-Rexes have been asked to death…
> >>>
> >>> First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?
> >>>
> >>> Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?
> >>>
> >>> Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…
> >> Most predators don't turn their noses up at eating free meals. That said, the idea of short arms for "defending" corpses is ridiculous.
> Some predators, notably lions an hyenas, take kills away from other
> predators, and this may form a fair fraction of their diets. Whether T.
> rex ever did such a thing is unclear, and I see no way of finding out.

Great, thanks all!

On Thursday, September 14, 2023 at 5:11:33 AM UTC-7, Sight Reader wrote:
> On Wednesday, September 13, 2023 at 8:01:13 AM UTC-6, John Harshman wrote:
> > On 9/13/23 6:37 AM, Sight Reader wrote:
> > > Lol… their arms are ridiculous too! I suppose, when it comes to explaining those tiny arms, one must “get used to disappointment”, as the Dread Pirate Roberts said…
> > >
> > > As to T-rex being primarily a scavenger, it sounds like that theory has pretty much died…
> > >
> > > On Tuesday, September 12, 2023 at 9:03:28 AM UTC-6, erik simpson wrote:
> > >> On Tuesday, September 5, 2023 at 9:08:44 AM UTC-7, Sight Reader wrote:
> > >>> Hello! Apologies if questions about scavenging T-Rexes have been asked to death…
> > >>>
> > >>> First question: I heard way back when someone postulated that T-Rex’s short little arms might be a response to defending a corpse: that is, longer arms would present more of bite target (and vulnerability) when fighting off other scavengers for the same corpse. I forgot who speculated this, but they said they’d need to run some statistics on the shortening of arms over time: does anyone know if anything came of this?
> > >>>
> > >>> Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?
> > >>>
> > >>> Thanks a ton, and apologies if these are naive or stupid questions… I still suck at this, as might have been obvious from my previous posts…
> > >> Most predators don't turn their noses up at eating free meals. That said, the idea of short arms for "defending" corpses is ridiculous.
> > Some predators, notably lions an hyenas, take kills away from other
> > predators, and this may form a fair fraction of their diets. Whether T.
> > rex ever did such a thing is unclear, and I see no way of finding out.
> Great, thanks all!

It may be worth noting that another dinosaur not especially closely related to Tyranosaurids also developed
short arms. These are the Carcharodontosaurid dinosaurs of Patagonia. They are well separated spatially and
temporally. The reasons for the convergent trait are still controversial, but are probably the same for both groups.

https://www.cell.com/current-biology/fulltext/S0960-9822(22)00860-0

Sight Reader wrote:

> Secondly, how big was the potential scavenging niche for T-Rex? Could a species as massive - and possibly energetic - as a T-Rex survive solely on scavenging all the big, dead bodies? Are there ecosystems that exist today where the top predators can fully meet their energy requirements solely by scavenging and, if so, what is generally true about the frequency and biomass of the corpses generated by such a system in relation to the biomass of the living?

T-Rex, in my pet theory, was the ultimate ambush hunter. It was a land crocodile.

Think of a crocodile... in the water... next to shore... looking like a harmless
log... animal approaches for a drink and >*BAM!*<

The crocodile springs out, drags it in & rolls around, tearing a huge chunk of
flesh out of the animal.

The T-Rex was built for strength & speed. But, if it ran for very long it risked
tripping, and many estimates have its head slamming into the ground,
after tripping, with enough force to kill it. But what if it was an ambush
hunter, running no more than, say, its own body length or two?

Secondly, it had a supreme sense of smell. So if there was anything dead
with a mile or so, it knew where it was.

So: Awesome sense of smell = scavenger

Binocular vision, all that strength and potential speed = hunter

-- --

https://jtem.tumblr.com/post/731734264911183872

Howdy howdy and thanks for the fascinating and kind thoughts! (cheers!)

On Friday, October 20, 2023 at 3:37:34 PM UTC-6, JTEM wrote:
> T-Rex, in my pet theory, was the ultimate ambush hunter. It was a land crocodile.
>
> Think of a crocodile... in the water... next to shore... looking like a harmless
> log... animal approaches for a drink and >*BAM!*<

ACK!! You’re going to give me nightmares! (afraid to look under his bed…)

This has me wondering… would it be reasonable to expect that T-rex would be limited to habitats with extensive cover? I would think something that large would need a fair amount of cover to avoid detection: if something like grass existed back then (had grass been invented yet?) it would have to have been some AWFULLY tall grass to hide something like a T-rex!

What sorts of paleoenvironments have T-rexes been recovered in? Have their remains been limited to swamps, forests, or other environments with extensive natural cover, or are they also found in deserts and such, where cover and ambush would be more difficult?

>
> The T-Rex was built for strength & speed. But, if it ran for very long it risked
> tripping, and many estimates have its head slamming into the ground,
> after tripping, with enough force to kill it.

This is true for me as well… I clearly wasn’t built for either strength OR speed, but I would probably trip and cave my head in if I tried to catch a plane in another concourse…

> But what if it was an ambush
> hunter, running no more than, say, its own body length or two?

Absolutely! But this also has me wondering about some other practicalities… if prey didn’t happen to wander right in front of T-rex, then I would think it would need to be capable of a stealthy approach. Would it be difficult for feet of that size and weight to avoid snapping a twig or two? Then, in regards to the actual ambush, T-rex would need to transition from complete stillness to explosive acceleration. Is it hard for something of that size to accelerate like that?

I don’t know the physics, but I (think?) weight and volume grow “cubically” with size while muscle strength only increases by the cross-sectional area (which, I would guess, would be only by the “square” of size) so that, as you get big, weight starts to win out over muscle. Would that make it exponentially more difficult for an animal of that size accelerate suddenly, much like a car trying to out-accelerate a motorcycle? Yes, the car may be able to catch the motorcycle in the end, but right at the starting gun, the motorcycle will have a temporary acceleration advantage until it is limited by its top speed and the car can start closing in.

Anyway, now you have me terrified of opening my door… I’m picturing a monstrous set of T-rex teeth suddenly snapping me in two the second I walk outside…

>
> Secondly, it had a supreme sense of smell. So if there was anything dead
> with a mile or so, it knew where it was.
>
> So: Awesome sense of smell = scavenger
>
> Binocular vision, all that strength and potential speed = hunter

Most def! T-rex is clearly evolved to judge distances and strike… it’s hard to see why you’d want to turn your eyes forward like that if there wasn’t immense evolutionary pressure to be accurate about SOMETHING… like catching me walking out of my door…!

Sight Reader wrote:

> This has me wondering… would it be reasonable to expect that T-rex would be limited
> to habitats with extensive cover? I would think something that large would need a
> fair amount of cover to avoid detection: if something like grass existed back then
> (had grass been invented yet?) it would have to have been some AWFULLY tall
> grass to hide something like a T-rex!

Jurassic Park, the film, got it all backwards. T-Rex had binocular vision and an amazing
sense of smell. The herbivores, and maybe I should say most herbivores (though I
can't think of any for whom this is NOT true) had their eyes on the side of their
heads. They were good at spotting MOTION. But if a T-Rex or anything else was
just lying there, they couldn't necessarily see it.

> > But what if it was an ambush
> > hunter, running no more than, say, its own body length or two?

> Absolutely! But this also has me wondering about some other practicalities… if
> prey didn’t happen to wander right in front of T-rex, then I would think it would
> need to be capable of a stealthy approach.

It could and almost certainly did scavenge.

It's also unlikely that they shared their metabolism with mammals or even birds.

It has been suggested that these later dinosaurs maybe started out "warm
blooded," grew quickly and then acquired a more "Cold blooded" metabolism.
But, being so large, they could have retained body heat and so lived as a
warm blooded animal without the overhead.

The point is, a T-Rex may not have required anywhere near as much food as
a mammal of the same body size.

> Yes, the car may be able to catch the motorcycle in the end, but right at
> the starting gun, the motorcycle will have a temporary acceleration
> advantage until it is limited by its top speed and the car can start closing in.

In your scenario they begin at the same time. In the case of an ambush
hunter, the prey can only start running AFTER you come after it.

If it's close enough, it has very little chance of survival.

A T-Rex only had to wound another dinosaur. It's mouth was so big, it
could create a massive wound which is either going to bleed out or
fester.. that powerful sense of smell telling the T-Rex exactly where to go
look.

> > Secondly, it had a supreme sense of smell. So if there was anything dead
> > with a mile or so, it knew where it was.
> >
> > So: Awesome sense of smell = scavenger
> >
> > Binocular vision, all that strength and potential speed = hunter

> Most def! T-rex is clearly evolved to judge distances and strike… it’s hard to
> see why you’d want to turn your eyes forward like that if there wasn’t
> immense evolutionary pressure to be accurate about SOMETHING… like
> catching me walking out of my door…!

Binocular vision really needed to judge distances. Yes, and telling you
precisely where something is. So with binocular vision the T-Rex could know
where it's prey was and how far away it was; both things any ambush hunter
needs to know.

Also: If we're talking herd animals, and there are many indications that we
are, they're not necessarily running away from you. Let's say the animal
closest to you flees in a line perpendicular to you... AND THEN others
behind it run along that very same line, seeing the lead animal flee they
follow it... bringing them to you!

-- --

https://jtem.tumblr.com/post/731796353021247489

On Saturday, October 21, 2023 at 11:18:52 PM UTC-6, JTEM wrote:
> It could and almost certainly did scavenge.
>
> It's also unlikely that they shared their metabolism with mammals or even birds.
>
> It has been suggested that these later dinosaurs maybe started out "warm
> blooded," grew quickly and then acquired a more "Cold blooded" metabolism..
> But, being so large, they could have retained body heat and so lived as a
> warm blooded animal without the overhead.
>
> The point is, a T-Rex may not have required anywhere near as much food as
> a mammal of the same body size.

I certainly wouldn’t want to keep scavenging a carcass if T-rex showed up! Perhaps, if I had a pack with me - maybe a gang of large pterosaurs, smaller tyrannosaurids or something like that - we might try to annoy T-rex away from the meal, but beyond that anyone who isn’t a rodent is going to have to clear out when T-rex arrives. I imagine he’s gotta be the King of the Carcass.

Could T-rex meet all of their dietary needs this way? I suppose T-rexes (and sauropods, for that matter) would never be able to eat enough if their metabolism needed the full amount that today’s mammals and birds require, but I’m no expert. I would guess SOMETHING would have to be different - that somehow they would have to be less than fully endothermic - but in exactly what way I wouldn’t know. For this reason, I suppose it’s pretty much impossible - at least for now - to reconstruct just how much food an average T-rex would need and whether it could get it soley from scavenging (beyond maybe grabbing some general statistics on predator-prey ratios). Certainly those fossils with healed T-rex bites would seem to indicate they did at least SOME hunting…

> In your scenario they begin at the same time. In the case of an ambush
> hunter, the prey can only start running AFTER you come after it.
>
> If it's close enough, it has very little chance of survival.
>
> A T-Rex only had to wound another dinosaur. It's mouth was so big, it
> could create a massive wound which is either going to bleed out or
> fester.. that powerful sense of smell telling the T-Rex exactly where to go
> look.
(Snip)
> Also: If we're talking herd animals, and there are many indications that we
> are, they're not necessarily running away from you. Let's say the animal
> closest to you flees in a line perpendicular to you... AND THEN others
> behind it run along that very same line, seeing the lead animal flee they
> follow it... bringing them to you!

OK, I’m having a little trouble grokking all of this… perhaps the best thing for me to do is try to put myself in T-rex’s shoes?

So let’s say I’m a T-rex and I’m hungry… yum yum yum yum! I’m in a forest, lots of cover for ambushes. Ha! Look! A herd of hadrosaurs in the clearing!

I can’t run at them from here: they’re too far away and faster than me. I’ll need to stay within the trees so they can’t see me approach. I take my first tiptoe step and…. SNAP CRACKLE POP! Ack! I weigh too much… dang branches! They heard that… they’ve pricked up. How can I possibly get close? This is a dang FOREST - there’s not a single clear footfall between here and there and no way for me to approach close enough to ambush!

If I don’t want to alert them to my approach, then I guess I’ll just have to crouch here at the edge of the forest and hope one of them happens to wanders into the clearing next to me by sheer chance. But what of are the chances of them actually being dumb enough to do that? Even if I’m undetected, I have no bait to draw them here, so they have no reason to want to wander over here. How can I ever get close enough to make up for my short range? Being an ambush predator of this size sucks!

But wait! One of them decided to be dumb enough to start coming over here just for the sake of argument! C’mon, a little closer… a little closer… yum yum yum yum… oh no! He’s starting to turn away! He’s still a good 40 yards/meters away… if I’m going to take him, it’s now or never!

I am stuck in his field of vision - hard NOT to be when the stupid thing has eyes on the side of its head - so I need to hold absolutely still so I don’t blow my cover, eliminating any hope of a running start. In other words, I have to go from being completely still and silent to being on top of him before he can react: the only head start I get will be his reaction time. I make my move: my cover of trees and branches thrashes and snaps with my huge bulk, my muscles strain to overcome my massive inertia, my claws skid in the dirt. He’s startled, but his reflexes aren’t THAT slow - certainly not enough to let someone MUCH heavier gain 40m on him. Clouds of dust burst as he claws the earth, and by the time my bulk bursts out of the woods, he has already equalized my speed and is pulling away. Not even worth snapping my teeth: he’s outta here.

I was also the only predator bursting forth for the herd to react to, so by instinct they’re all moving away from me. I’m screwed. Now, maybe if my cousin T-rex Sue had initially jumped at them from a different direction, I could take advantage of the distraction to burst out relatively undetected and catch them with their momentum going the wrong way: even at considerable distance, once going at full speed, they’ll find that they’re too big to do a 180 and I might be able to snap a hole in one of them before they can reverse. However, Sue told me I was supposed to prove I could ambushes completely on my own today and stood me up. Never really liked her anyway…

Man, this is harsh, even in a forest or swamp with a lot of cover, never mind out in open environments. If anyone finds our T-rex remains in open terrain, I figure I either made my living completely by scavenging or got Sue and my other buddies to work as a pack; otherwise I just don’t see how we could do it!

Thoughts? Oh wait… someone’s at the door… I think I hear them saying, “yum yum yum yum…” Be right back…

Sight Reader wrote:

> So let’s say I’m a T-rex and I’m hungry… yum yum yum yum! I’m in a forest, lots of cover
> for ambushes. Ha! Look! A herd of hadrosaurs in the clearing!

A hadrosaur weighed 8 to 9 tons -- more than an African elephant.
I don't think a herd of these things is going to be relatively silent.

And they probably didn't have great hearing, either.

Doing the Google just now, suspicions are confirmed: They were
more than likely tuned into the low frequencies.

They didn't have our range of hearing. And there's no reason to
suspect that they were very good at pinpointing sources...

> I can’t run at them from here: they’re too far away and faster than me. I’ll
> need to stay within the trees so they can’t see me approach. I take my
> first tiptoe step and…. SNAP CRACKLE POP! Ack! I weigh too much… dang
> branches! They heard that… they’ve pricked up. How can I possibly get close?
> This is a dang FOREST - there’s not a single clear footfall between here
> and there and no way for me to approach close enough to ambush!

If, as an adult, you have all the nutritional needs of a cold blooded animal,
you could just lie down in a promising spot, maybe even for days, and not
move. If you smell something dead or very wounded, you can go have
yourself a meal. If not, just snag the first dinosaur that wanders by.

> I was also the only predator bursting forth for the herd to react to, so by
> instinct they’re all moving away from me.

They would all most likely be moving in the direction of the first one to
run. So if you approach it at a right angle, and it runs forward, this will
take the animals behind it directly into your path.

But, like I said; I always pictured a land crocodile. They just lie there,
waiting for something to get too close then SPRING forward, taking a
huge chunk out of its flesh.

They didn't even have to kill it. If the wound was bad enough, it was
going to bleed out or fester, and the animal was going to eventually drop.
At which point, that powerful sense of smell will tell it exactly where
dinner is laying..

-- --

https://jtem.tumblr.com/post/731734264911183872

On Monday, October 23, 2023 at 8:11:02 PM UTC-7, JTEM wrote:
> Sight Reader wrote:
>
> > So let’s say I’m a T-rex and I’m hungry… yum yum yum yum! I’m in a forest, lots of cover
> > for ambushes. Ha! Look! A herd of hadrosaurs in the clearing!
> A hadrosaur weighed 8 to 9 tons -- more than an African elephant.
> I don't think a herd of these things is going to be relatively silent.
>
> And they probably didn't have great hearing, either.
>
> Doing the Google just now, suspicions are confirmed: They were
> more than likely tuned into the low frequencies.
>
> They didn't have our range of hearing. And there's no reason to
> suspect that they were very good at pinpointing sources...
> > I can’t run at them from here: they’re too far away and faster than me. I’ll
> > need to stay within the trees so they can’t see me approach. I take my
> > first tiptoe step and…. SNAP CRACKLE POP! Ack! I weigh too much… dang
> > branches! They heard that… they’ve pricked up. How can I possibly get close?
> > This is a dang FOREST - there’s not a single clear footfall between here
> > and there and no way for me to approach close enough to ambush!
> If, as an adult, you have all the nutritional needs of a cold blooded animal,
> you could just lie down in a promising spot, maybe even for days, and not
> move. If you smell something dead or very wounded, you can go have
> yourself a meal. If not, just snag the first dinosaur that wanders by.
> > I was also the only predator bursting forth for the herd to react to, so by
> > instinct they’re all moving away from me.
> They would all most likely be moving in the direction of the first one to
> run. So if you approach it at a right angle, and it runs forward, this will
> take the animals behind it directly into your path.
>
> But, like I said; I always pictured a land crocodile. They just lie there,
> waiting for something to get too close then SPRING forward, taking a
> huge chunk out of its flesh.
>
> They didn't even have to kill it. If the wound was bad enough, it was
> going to bleed out or fester, and the animal was going to eventually drop..
> At which point, that powerful sense of smell will tell it exactly where
> dinner is laying..
>
>
>
> -- --
>
> https://jtem.tumblr.com/post/731734264911183872
A cautionary note: JTEM is mainly (maybe completely) a troll. He knows little, reads less and
is generally inaccurate in many of the things he says. Often he just clips everything you may say
and spews insults. Best left alone.

As you probably already know, T Rex was warm-blooded, and its hunting techniques changed as
it matured. Juveniles were cursorial, adults ambushed.

erik simpson wrote:
> A cautionary note:

You're a loser. Cowering behind sock puppets, can't even focus on discussions,
you have to throw your infantile "Taunts" instead... might as well climb into that
grave because you're already dead.

Now pretend you have an IQ reaching into the double digits and focus on the
topic at hand. Try to say something intelligent -- the operative word being try.

The T-Rex displays traits advantageous to both a predator and a scavenger.
What your excessively limited intellect never grasped is that dinosaurs were
not humans. They couldn't see the world as humans saw them, and neither
could they hear it the way we do.

You're an embarrassment, which you know and hence the sock puppets.

-- --

https://jtem.tumblr.com/post/731796353021247489

Hey again guys! Thanks to everyone for being so kind in pitching in… sorry it’s been a while, but we’ve had a zillion student absences and, unlike college, where absences are the student’s problem, in secondary school, absences are the TEACHER’s problem (especially when it comes to math), meaning that I’ve been very distracted…

On Monday, October 23, 2023 at 9:11:02 PM UTC-6, JTEM wrote:
> Sight Reader wrote:
>
> > So let’s say I’m a T-rex and I’m hungry… yum yum yum yum! I’m in a forest, lots of cover
> > for ambushes. Ha! Look! A herd of hadrosaurs in the clearing!
> A hadrosaur weighed 8 to 9 tons -- more than an African elephant.
> I don't think a herd of these things is going to be relatively silent.
>
> And they probably didn't have great hearing, either.
>
> Doing the Google just now, suspicions are confirmed: They were
> more than likely tuned into the low frequencies.
>
> They didn't have our range of hearing. And there's no reason to
> suspect that they were very good at pinpointing sources...

This brings up interesting ideas on several accounts. Firstly, the notion that there was no evolutionary pressure for hadrosaurs to develop pinpoint hearing. Secondly… would that mean T-rex would be limited to attacking dinosaurs with poor hearing? Then an even WEIRDER idea occurs: could the T-rex’s ecosystem be simply louder than today’s world? I assume that one would be easy to disprove: all you’d have to do is find another animal in the same ecosystem who clearly relied on hearing to detect and pinpoint others.

> > I was also the only predator bursting forth for the herd to react to, so by
> > instinct they’re all moving away from me.
> They would all most likely be moving in the direction of the first one to
> run. So if you approach it at a right angle, and it runs forward, this will
> take the animals behind it directly into your path.
>
> But, like I said; I always pictured a land crocodile. They just lie there,
> waiting for something to get too close then SPRING forward, taking a
> huge chunk out of its flesh.
>
> They didn't even have to kill it. If the wound was bad enough, it was
> going to bleed out or fester, and the animal was going to eventually drop..
> At which point, that powerful sense of smell will tell it exactly where
> dinner is laying..

Hey! I saw a scene like that on that new Netflix “Life on Our Planet”: T-rex tried springing out from the woods with its two young running interference but the Triceratops was able to get back to its herd. Certainly, if T-rex actually worked in packs, you’d solve the problem of being able to catch faster prey: otherwise, as you suggest, we’d probably need some “slow metabolism” T-rexes capable of going for days, weeks or perhaps longer on scavenging alone. Of course, I only recall hearing that juvenile T-rexes were known to operate in groups, not adults T-rexes or Triceratops…

Sight Reader wrote:

> This brings up interesting ideas on several accounts. Firstly, the notion that
> there was no evolutionary pressure for hadrosaurs to develop pinpoint hearing.

We have their physical remains. We have little idea of what pressures
they were under, and what genetic capacity they had to adapt to said
imagined pressures.

> Secondly… would that mean T-rex would be limited to attacking dinosaurs
> with poor hearing?

Why? Is that something true for lions? Or wolves?

Last I checked, it was never an issue.

> Then an even WEIRDER idea occurs: could the T-rex’s ecosystem be simply
> louder than today’s world?

Of course it could. But right now we're studying human imagination, not
dinosaurs.

> I assume that one would be easy to disprove: all you’d have to do is find
> another animal in the same ecosystem who clearly relied on hearing to detect
> and pinpoint others.

Or you can just look at predators & prey today.

> otherwise, as you suggest, we’d probably need some “slow metabolism” T-rexes
> capable of going for days, weeks or perhaps longer on scavenging alone.

They clearly had hunting adaptations.

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