More Tyrannosaur Stupidity

[Elfdart]

I can see them charging a 30 ton saraupod and breaking its neck with their massive maw.

I couldn't. T-rex didn't coexist with any sauropods as far as I know.[/nitpick]

Alamosaurus was around in the latest part of the Cretaceous. Not that it matters, since some of the later model duckbills were as large as some of the mid-sized sauropods. Shantungosaurus was over 50 feet long, as was one type of Lambeosaur -with Anatotitan and Edmontosaurus not far behind.

Large contemporary predators can often subsist by stealing the kills of other predators, so even if the Rex magically can't catch anything himself, he can sure scare people away from their kills.

True, but any large predator will starve if it has to rely on the kills of other animals in order to eat. Even if was possible, it creates a new problem: What predator was tough enough back then to kill the large duckbills and ceratopsians, but was too weak to fight off a tyrannosaur coming to steal their food?

If the tyrannosaurs had such a powerful sense of smell, then the wolf-like style of hunting (alone or in groups) would make sense. If an ambush draws blood but doesn't kill immediately, the hunter trots after the victim and finishes it off. If T.rex's sense of smell is half what it's supposed to be, it could hound its victims to death without having to sprint at all.

I'd also point out that Albertosaurus was much more lightly built than its larger cousin and if any creature hunted the ostrich-mimics, they did.

[God Fearing Atheist]

The way I understand it, birds, dromaeosaurs, and their ilk are all classified into a single group within Reptilia.

Almost every study has recovered a clade in which dromaeosaurids and troodontids (together called Deinonychosauria) are the sister group to Archaeopteryx and all other birds. In other words, deinonychosaurians are the most recent common ancestor of birds, but are not birds themselves.

[God Fearing Atheist]

All of taxonomy is educated guess-work, but that's fairly credible.

The science of evolutionary relationships is called phylogenetics, not taxonomy. Phylogenetics is a data-based science with an objective methodology, and is anything but guess work.

I doubt very much that the maniraptors are direct descendents of Archaeopteryx (which appears to be a bit of an evolutionary dead-end), but they may well be closely related.

It is actually impossible to test the hypothesis that Archaeopteryx (or any terminal taxon, for that matter) is directly ancestral to any other. The best science can do is posit and test patterns of shared common ancestry.

The interesting thing is that the dromaeosaurs have several skeletal features that are much closer to modern birds than the equivalent features of Archaeopteryx.

And Archaeopteryx shares derived characters with other birds absent from dromaeosaurids. The question is, which displays more derived characters, and is therefore most parsimoniously explained as sharing more recent common ancestry with them. As it currently stands, Archaeopteryx always turns out to be the winner.

So if we think of Archaeopteryx as being a bird (as opposed to a non-avian dinosaur) then it begs the question of why we consider dromaeosaurs non-avian dinosaurs.

What is and is not a bird is a matter entirely different than the phylogenetic relationships between the two groups. Being a "bird" is a matter of convention; there is nothing in nature that demands we use any particular word to refer to any particular taxon. Rather, it's simply a fluke of history. Archaeopteryx was discovered and called a bird first.

For all we know, they could have been totally feathered, as well.

The basal-most members (e.g. Microraptor, NGMC 91, Sinornithosaurus) undoubtedly were.

[God Fearing Atheist]

I heard once that Maniraptorids...

[nitpick]Acceptable conjugates of Maniraptora are maniraptor and maniraptoran. The "id" ending is only applied to those taxa which are, or whose names were derived from, the Linnaean family rank.[/nitpick]

...might be descendents of Archaeopteryx (which I heard shared the Dromaeosaurid's distinctive retractable 2nd toe claw), making them effectively birds. Should I give any credence to that theory?

Firstly, Archaeopteryx and deinonychosaurians sharing that hyperextendable second pedal digit (they do) cannot show that dromaeosaurids are any more closely related to extant birds than Archaeopteryx.

As far as the hypothesis itself goes, no, you should not pay it any attention, at least until someone corroborates it empirically.

[wolveraptor]

As far as the hypothesis itself goes, no, you should not pay it any attention, at least until someone corroborates it empirically.

Well I did read it in a Gregory S. Paul book. The man is a bit of a wanker, but he draws well.

[Anguirus]

Thanks for clearing that up, GFA.

[God Fearing Atheist]

As far as the hypothesis itself goes, no, you should not pay it any attention, at least until someone corroborates it empirically.

Well I did read it in a Gregory S. Paul book. The man is a bit of a wanker, but he draws well.

Yeah. As nice as his pictures are, he unfortunately falls into the same trap as Alan Feduccia; he fails to posit explicit phylogenetic hypotheses and test them against the data using an objective methodology.

[Darth Wong]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

[wolveraptor]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

As long as you brought that up, I'd think that a T-rex, if it didn't die of hypoxia due to present day oxygen levels being lower than Cretaceous ones, would gorge on slow-moving elephants, who have no defences against a predator of equal size.

[starfury]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

Seems obvious enough, only that wanker Horner contiunues to Belive that T.Rex is still too Slow to take down even those ponderous prey, apparantly.

[Elfdart]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

Kind of like the joke about the two hikers running from a bear. One doesn't need to be faster than the bear -just faster than the other hiker. You can see the same pattern with Smilodon. It wasn't built for sprinting like the pantherine cats because its main victims were animals that couldn't run any faster: mammoths, mastodons, sloths, etc.

[Flagg]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

Seems obvious enough, only that wanker Horner contiunues to Belive that T.Rex is still too Slow to take down even those ponderous prey, apparantly.

IIRC someone posted here awhile back that he pretty much admitted he's full of shit on the pure scavanger thing and just said it on TV to try to de-hype the T-Rex.The idea that it might have been a scavanger much, if not most of the time that used is incredible sense of smell and sheer mass to find and steal the kills of other predators isn't really all that far out there. It's the idea that it's primarily a scavenger that's just bullshit. Lions commonly steal the prey of smaller, faster carnivores.

[Napoleon the Clown]

<trim>
It attacked a gallimimus from the treeline and the raptor was not aware of the T-Rex until it was in its jaws, so both were effectively ambushed. The only 2 humans shown being directly injured or killed by the T-Rex were Genarro, who was not moving, and Malcolm, who appears to have been thrown into their air either by a kick or the head when destroying the hut. I don't recall seeing it spinning around or turning much.

Um, it was fast enough to snag humans, raptors, and other agile targets. And it pulled a 180 in under two seconds. It made the bastard out to be more agile than a crocodile. That doesn't seem too accurate to what this study suggests.[/quote]
I point out when it turned around because of Malom yelling and waving a flair and when it was in a fight with raptors.

One problem with the croc/Komodo Dragon thing... Those are both small enough that they can be very fast lungers. A six ton animal, not so much.

A large crocodile can weigh nearly 2,000 pounds and there are extinct examples that are at least as large as a T-Rex (members of the Sarcosuchus genus could weigh up to 8,000 kilos).

Guh, I should have typed "relatively small enough"...

There's also a big difference between five to ten miles per hour. Not to mention wolves actually posses the intellect to hunt in packs, whereas t-rex may not have.

Hard to say. They could have been fairly stupid animals otherwise, but if they had brains adapted to group hunting, they could hunt in groups. For instance, squirrels apparently can't learn that running in front of cars is a stupid move, but they can memorize the locations of hundreds of nut caches.[/quote]
True enough.

[Johonebesus]

It seems rather obvious that the T.Rex's prey was probably huge and ponderous too, so it didn't need to be as fast. Against the smaller, faster prey of today, it would be hopeless.

Kind of like the joke about the two hikers running from a bear. One doesn't need to be faster than the bear -just faster than the other hiker. You can see the same pattern with Smilodon. It wasn't built for sprinting like the pantherine cats because its main victims were animals that couldn't run any faster: mammoths, mastodons, sloths, etc.

I wonder if Tyrannosaurs would have any chance at all preying on elephants or other recent mega fauna. Not long ago I caught a scene on one of the Discovery channels with a medium sized theropod going after a mixed herd of modern and hairy elephantines.

[Elfdart]

I don't know. Maybe the tusks could be used as weapons if the herd turned and faced the animal en masse. Sometimes predators wuss out. I saw a warthog that a lion had dead in its sights just turn and chase the big cat away. When that happened in Born Free I thought it was bullshit, but when it happened on the Discovery Channel, I came to the conclusion that what happens is a predator becomes confused when its intended victim does something unexpected. The lion looked flummoxed by the warthog when it stopped running away, turned and chased the lion.

[Johonebesus]

I'm more curious as to whether a tyrannosaur could catch an elephant or any other big mammal. I know that elephants aren't terribly fast compared to deer or even giraffes, but they can run, and between their noses and ears it's pretty hard to sneak up on them. Upon a time it was stated as fact that dinosaurs simply couldn't keep up with mammals. I wonder what would really happen if you dropped some dinosaurs in the modern world (never minding disease).

[Isolder74]

Not this guy again. The man's only real evidence against Rex being a killer, he discounts their mouth for some reason, is that Rex had a large olfactory node and tiny little arms that can't help Rex grab onto anything.

On that note I refer you all to the MIGHTY Polar Bear one the largest preditors on Earth, other than the Orca, and guess what it also has the most sensitive nose of any mammal. The polar bear is known to be almost a pure predator.

Also if he;s saying that Rex because he has no arms can't catch and hold onto something, I refer you to have him watch a chicken chase does and catch bugs with its beak. It seems to manage just fine and they never use their arms.

Using Raptors as an example of what a predator must alway turn out to be would make a croc a Scanavger(its gcould never chase down a gazelle). Also its a myth that Hyena are scavangers. They are not.

[wolveraptor]

I don't know. Maybe the tusks could be used as weapons if the herd turned and faced the animal en masse. Sometimes predators wuss out. I saw a warthog that a lion had dead in its sights just turn and chase the big cat away. When that happened in Born Free I thought it was bullshit, but when it happened on the Discovery Channel, I came to the conclusion that what happens is a predator becomes confused when its intended victim does something unexpected. The lion looked flummoxed by the warthog when it stopped running away, turned and chased the lion.

Elephants would be totally unprepared for animals of their own size, though. They could probably be panicked into running and revealing their backsides.

[Napoleon the Clown]

I don't know. Maybe the tusks could be used as weapons if the herd turned and faced the animal en masse. Sometimes predators wuss out. I saw a warthog that a lion had dead in its sights just turn and chase the big cat away. When that happened in Born Free I thought it was bullshit, but when it happened on the Discovery Channel, I came to the conclusion that what happens is a predator becomes confused when its intended victim does something unexpected. The lion looked flummoxed by the warthog when it stopped running away, turned and chased the lion.

Boars are very dangerous critters. It wasn't so much that the boar did something out of the ordinary as much as it showed itself to be a dangerous prey item. Their tusks can kill quite easily. Any smart predator will avoid prey that can actually fight back effectively. And boars a smart as well. The most dangerous animals are the ones that fight most viciously, not the ones that are fastest, strongest, and packing the most lethal weapons. That's probably why grizzlies flee from a mother cougar or a pack of lions book it when they come upon a ratel den. That's why alley cats have been known to royally fuck over dogs that incite their ire. The bigger stronger animal may be able to win in the end but it'll cost them a lot of blood and possibly their life in the long run.


Elephants are smart, so I don't know just how they would react to something like a T-Rex. If they're capable of abstract thinking they'd have a chance. Alas, I have no clue just where they rank on that. According to the Wiki (grain of salt now) they learn pretty much everything they do.

About the T-Rex's arms, I recall reading something about them being strong enough to actually effectively grip prey once they get in close enough. I'll be damned if I can remember where I read this though.

[Elfdart]

I'm more curious as to whether a tyrannosaur could catch an elephant or any other big mammal. I know that elephants aren't terribly fast compared to deer or even giraffes, but they can run, and between their noses and ears it's pretty hard to sneak up on them. Upon a time it was stated as fact that dinosaurs simply couldn't keep up with mammals. I wonder what would really happen if you dropped some dinosaurs in the modern world (never minding disease).

Elephants can't run, but when they do their fast shuffle, they can hit about 20mph. These new estimates for T.rex would mean that the predator could still catch up with them without hounding them. Considering that T.rex's main prey were Triceratops, which was about the same size as an African elephant and duckbills, which could be almost twice as big, size wouldn't be an issue.

Elephants would be totally unprepared for animals of their own size, though. They could probably be panicked into running and revealing their backsides.

Elephants usually respond to threats by charging, preferably in a group. In East Africa, they had a nasty habit of ramming trains, a habit that killed many people as well as elephants. Elephants are among the smartest animals, but their fight-or-flight instincts are more of less hard wired. Even if they weren't pre-programmed to counterattack, they are probably smart enough to realize that fighting back is their only chance. If musk oxen can figure that out, I'd assume elephants could, too.

Boars are very dangerous critters. It wasn't so much that the boar did something out of the ordinary as much as it showed itself to be a dangerous prey item. Their tusks can kill quite easily. Any smart predator will avoid prey that can actually fight back effectively. And boars a smart as well.

The thing that makes pigs dangerous is their willingness to fight back. Collared peccaries are infamous for ganging up on predators. The Cape Buffalo even more so.

The most dangerous animals are the ones that fight most viciously, not the ones that are fastest, strongest, and packing the most lethal weapons. That's probably why grizzlies flee from a mother cougar or a pack of lions book it when they come upon a ratel den. That's why alley cats have been known to royally fuck over dogs that incite their ire. The bigger stronger animal may be able to win in the end but it'll cost them a lot of blood and possibly their life in the long run.

That's true, but I think predators have a "oh shit" switch in their brains that goes off when their victims turn and come at them. You see this in bears when humans scare them off by turning to face them, screaming and flailing their arms around. Some of it might be a tripwire that warns them something funny is going on, maybe as a built-in precaution against critters that don't run away, but can still fuck them up (skunks, porcupines).

Elephants are smart, so I don't know just how they would react to something like a T-Rex. If they're capable of abstract thinking they'd have a chance. Alas, I have no clue just where they rank on that. According to the Wiki (grain of salt now) they learn pretty much everything they do.

see above

About the T-Rex's arms, I recall reading something about them being strong enough to actually effectively grip prey once they get in close enough. I'll be damned if I can remember where I read this though.

Gregory Paul put it best when he wrote that the atrophied little arms of tyrannosaurs weren't important to them, so why should we spend so much time on them? I think he's right. I wonder if an alien species that looked at human skeletons would spend much time wrangling over the human tailbone.

[wolveraptor]

Elephants usually respond to threats by charging, preferably in a group. In East Africa, they had a nasty habit of ramming trains, a habit that killed many people as well as elephants. Elephants are among the smartest animals, but their fight-or-flight instincts are more of less hard wired. Even if they weren't pre-programmed to counterattack, they are probably smart enough to realize that fighting back is their only chance. If musk oxen can figure that out, I'd assume elephants could, too.

I think the musk ox's defensive ring is more instinctive than thought out, if that was what you were referring too. Elephants are smart, but an isolated one could easily be panicked, I think. Isolation of prey is a basic principle of predation, as well as picking on the young, old, and sick.

Though I've always wondered about the last one. Wouldn't it be dangerous to feed on the meat of sick prey? One would think that the desire to attack sick prey would be evolutionarily weeded out as the predators who did just that died of their prey's diseases.

[Akhlut]

I don't know. Maybe the tusks could be used as weapons if the herd turned and faced the animal en masse. Sometimes predators wuss out. I saw a warthog that a lion had dead in its sights just turn and chase the big cat away. When that happened in Born Free I thought it was bullshit, but when it happened on the Discovery Channel, I came to the conclusion that what happens is a predator becomes confused when its intended victim does something unexpected. The lion looked flummoxed by the warthog when it stopped running away, turned and chased the lion.

Warthogs also have tusks that can be over 6 inches long and razor sharp. A warthog running away from a lion means that those tusks aren't aimed at a lion. Lions may be mighty hunters, but they generally know when to give up when they might get a horrible injury out of their intended prey.

So, yeah, predators will sometimes avoid prey smaller than them if said prey has sharp, pointy bits, to say nothing of larger prey with sharp, pointy bits.

[Akhlut]

GHETTO EDIT: Nevermind, I didn't read down the thread far enough before replying. Napoleon already said what I wanted to.

[wolveraptor]

Though pack hunters like the lion are less likely to give up chase against dangerous prey simply because they can rely on their pride to feed them while they're injured. Tigers, however, can't afford to be too injured to feed. In my opinion, this is reflected in their quick-and-clean killing method (severing the spinal cord with a bite to the neck)* compared to the lion's long, drawn-out, suffocation method.

*Interesting tidbit: cats that hunt like the tiger often have a very specific distance between their two canine teeth, so that their teeth fit perfectly into the vertebral gaps of their primary prey's neck.

[Akhlut]

Though I've always wondered about the last one. Wouldn't it be dangerous to feed on the meat of sick prey? One would think that the desire to attack sick prey would be evolutionarily weeded out as the predators who did just that died of their prey's diseases.

Depends on what the prey is sick with. As I recall hearing from some special on predators on Discovery Channel or Animal Planet, that during anthrax outbreaks in Africa, a lot of predators die when they scavenge from anthrax infected carcasses. Of course, vultures and hyenas are rarely affected by such things due to their outrageously effective immune systems and their intensely acidic stomachs. However, parasitic infections which kill prey to get into predators, would have evolved to not be such a burden on their final hosts as to kill them.

I also imagine a lot of predators have a lot of very powerful immune responses in their GI tract to prevent such things from happening. Natural selection would have chosen animals that can exploit free meals.