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Post by Infinity Blade on Apr 3, 2014 5:30:21 GMT 5
But again, Postosuchus was not cold blooded. I want to see this supposed evidence that suggests Postosuchus would move like modern reptiles. I am finding this very hard to believe. To your other post, blaze's last post here clears the evidence for endothermy up. Evidence points to endothermy. Why would you find it hard to believe that a distant relative of modern reptiles would move differently? It would be far more likely that this reptile moves more like a croc or lizard than anything else. If anything the smaller forelimbs is a dead give away that this animal would most likely be unable to survive today. It would be unable to catch prey needed to sustain it, most likely. Even the komodo dragon must use its bacteria to take down prey, crocs use the element of surprise from the water. I just don't see a practical place for this predator in todays world. Obviously I could be wrong, but I definitely would be astonished if this animal could maintain a pace fast enough to catch any mid sized mammal. Maybe if it adapted to the environment, but how could this reptile even stalk on land. It would have its hind section so high off the ground if it lowers its head in a ambush poster. Getting a little off topic, but its interesting to think about. Just look at their limb posture. Notice how the rauisuchian's limbs don't sprawl out like a varanid or modern crocodilian. They're erect, just like a mammal's.    If anything, it'll probably be moving like a theropod.  What does being able to survive today have anything to with who would win in a fight between Postosuchus and a tiger? While you do acknowledge it, it is absolutely irrelevant. And let me make one thing clear: I don't back Postosuchus. I too think the tiger wins. But not so much as mobility and metabolism, but its better forelimbs and claws as extra weapons that could be used to better control Postosuchus as opposed to only a set of jaws. |
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Carcharodon
Junior Member
Allosauroidea Enthusiast
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Post by Carcharodon on Apr 3, 2014 6:33:00 GMT 5
Postosuchus might only have jaws, but these jaws are pretty devastating. It literally outclasses the tiger in the biting department, it could probably even simply fit the tiger's head in its jaws. Now the tiger's grappling forelimbs with claws could be a challenge, but i think postosuchus can nullify that if it can bite the cat's forelimbs. And i would rather believe in this restoration for postosuchus, its bulkier than that one shown in the size comp with the tiger.  |
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Post by Supercommunist on Apr 3, 2014 7:23:14 GMT 5
One thing to consider is that big cats weren't built to grapple with animals whose primary method of attack and defence were their jaws. Crocodiles and hippos are practically the only animals they encounter with this kind of design and in conflicts with them they seem to try and avoid engaging them from the front and instead try to outflank them, so I am not really sure if its in the tiger's best intrest to wrestle with the postosuchus.
Also the scales of the postosuchus would make it difficult for the tiger's claws to get a decent grip in the first place.
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blaze
Paleo-artist 
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Post by blaze on Apr 3, 2014 9:34:33 GMT 5
Because reptiles is a much more inclusive group than mammals is, birds are reptiles too you know? you can't infer the physiology of an animal based on broad generalizations from considerably distantly related taxa, you do so from looking at their closest relatives and their anatomy and modern crocodiles and rauisuchians show obvious differences, in particular the structure of their pelvis which shows a unique specialization for an erect stance like that of mammals, the anatomy of their feet and trackways also point to them being animals that walked with a narrow gait with their limbs held under their bodies, there are no erect-limbed animals that are cold-blooded btw.
Modern crocodiles are oddballs, if you follow their evolutionary history you see that those "reptilian" characteristics that makes them somewhat similar to lizards were evolved and not present in their ancestors, basal crocodylomorphans were small animals with an erect stance that walked on their toes and had long cursorial legs not much different from those of dogs, their hips, shoulders, limbs and feet showed adaptations similar to those seen in mammals, all of this adaptations will be wasted and impossible in a cold-blooded animal so they have to have been warm blooded.
Isn't it funny? crocs "invented" the dog morphotype not only before dogs existed but also before mammals were a thing at all.
The last paragraph and sentence is too make my point that you have to use more than just, "this living (distantly related) relative is like this so the extinct one was like that too", because while Postosuchus had an erect stance and is very likely to have been more energetic and athletic than modern crocs it still had platigrade feet and its vertebral column wasn't very flexible so yeah, the tiger is more agile without a doubt.
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pckts
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Post by pckts on Apr 3, 2014 23:06:50 GMT 5
One thing to consider is that big cats weren't built to grapple with animals whose primary method of attack and defence were their jaws. Crocodiles and hippos are practically the only animals they encounter with this kind of design and in conflicts with them they seem to try and avoid engaging them from the front and instead try to outflank them, so I am not really sure if its in the tiger's best intrest to wrestle with the postosuchus. Also the scales of the postosuchus would make it difficult for the tiger's claws to get a decent grip in the first place. Polar bears are specifically said to fight much more with their mouth's than other bears. Tigers and lions have killed polar bears, grizzlies, crocs, hippos, elephants, rhinos, monitors etc..... They are specifically designed to grapple, bite and kill. If anything, "grappling" is by far in the tigers favor. They have 4 limbs that are specifically designed to grapple and a mouth that is every bit as deadly if it gets a hold of you. Now on to the question about "what does it matter if a animal could survive today" I posed that question because I think it has to do with evolution. Evolution is trial and error, to be able to live in todays world, these animals had to evolve and become "better". There is a reason the land is now ruled by mammals. I see no way of looking at that dinosaur and thinking it would be nearly agile enough to take on a cat. Not only that, but what happens if/when the dino is put on his back. Watch a lion or tiger fight off their back, they are every bit as deadly if not even more so. A dino with stout front limbs and long back limbs is going to have a rough time standing after getting knocked down, let alone be able to bend its spine in ways to deter a tiger from getting a killer bite on the throat. |
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pckts
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Post by pckts on Apr 3, 2014 23:17:34 GMT 5
Because reptiles is a much more inclusive group than mammals is, birds are reptiles too you know? you can't infer the physiology of an animal based on broad generalizations from considerably distantly related taxa, you do so from looking at their closest relatives and their anatomy and modern crocodiles and rauisuchians show obvious differences, in particular the structure of their pelvis which shows a unique specialization for an erect stance like that of mammals, the anatomy of their feet and trackways also point to them being animals that walked with a narrow gait with their limbs held under their bodies, there are no erect-limbed animals that are cold-blooded btw. Modern crocodiles are oddballs, if you follow their evolutionary history you see that those "reptilian" characteristics that makes them somewhat similar to lizards were evolved and not present in their ancestors, basal crocodylomorphans were small animals with an erect stance that walked on their toes and had long cursorial legs not much different from those of dogs, their hips, shoulders, limbs and feet showed adaptations similar to those seen in mammals, all of this adaptations will be wasted and impossible in a cold-blooded animal so they have to have been warm blooded. Isn't it funny? crocs "invented" the dog morphotype not only before dogs existed but also before mammals were a thing at all. The last paragraph and sentence is too make my point that you have to use more than just, "this living (distantly related) relative is like this so the extinct one was like that too", because while Postosuchus had an erect stance and is very likely to have been more energetic and athletic than modern crocs it still had platigrade feet and its vertebral column wasn't very flexible so yeah, the tiger is more agile without a doubt. The flexibility of the spine as well as the smaller clavicle bones give the tiger room for massive muscle, speed and flexibility while being such a large predator. What about this dinosaur is adapted for flexibility and speed? It obviously runs on 2 legs which of course means it will be slower than a animal of equal size who runs on 4. It's weight distribution is specifically in the front and back section, which means when it moves one direction it will take some massive force to change directions. So obviously cutting angles or corners as well as jumping from side to side or avoiding danger is a problem for this creature. I also doubt it could move like a therapod as well. Its tail is so long and head is so massive that standing upright seems impractical for this animal, the long neck and downward curvature of the spine make me think it would carry its head similar to that of a tiger. More of a droopy downward faced head. |
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Post by creature386 on Apr 3, 2014 23:38:49 GMT 5
Rauisuchian, not dinosaur! Anyway, the evolution argument is invalid because evolution is no straight race, but a process often interrupted by mass extinctions, restarts and not always the same evolution pace. Different habitats require different adaptations. Formidable fighting skills are useful in open and densely inhabited areas (an example would be South Africa) where the arms race between predator and prey, as well as the competition between the predators should go on pretty quickly. However, all these fighting/hunting skills become useless when the water and the vegetation disappears. Indeed, rauisuchians were quite well adapted for the savannah story: books.google.de/books?id=Npp7EWkJhcwC&lpg=PP1&hl=de&pg=PA359#v=onepage&q&f=falseThe reason why stem crocodile rauisuchians went is unclear, but it is assumed that it had something to do with breathing issues in the end of the Triassic. |
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Post by Infinity Blade on Apr 4, 2014 0:14:43 GMT 5
"There's a reason the land is now ruled by mammals".
Yeah, the K-Pg extinction event! Take that out of the equation and I can almost guarantee you that reptiles would still be the most dominant vertebrate clade on the planet.
I remember something saying something like "evolution is not a process from good to better. Evolution is a process from doing well in this environment, to doing well in that environment". Evolution is not an argument.
As for movement, the head and body balancing one end, the tail balancing the other. Is it so difficult to visualize that? Whether or not it will move or turn as fast as a tiger is not the thing here. In fact, I have absolutely no problem believing the tiger will be superior in this regard. What I have a problem with is the over-generalization that because it must be a reptile we're familiar with, that it must move like one.
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pckts
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Post by pckts on Apr 4, 2014 1:09:27 GMT 5
"There's a reason the land is now ruled by mammals". Yeah, the K-Pg extinction event! Take that out of the equation and I can almost guarantee you that reptiles would still be the most dominant vertebrate clade on the planet. I remember something saying something like "evolution is not a process from good to better. Evolution is a process from doing well in this environment, to doing well in that environment". Evolution is not an argument. As for movement, the head and body balancing one end, the tail balancing the other. Is it so difficult to visualize that? Whether or not it will move or turn as fast as a tiger is not the thing here. In fact, I have absolutely no problem believing the tiger will be superior in this regard. What I have a problem with is the over-generalization that because it must be a reptile we're familiar with, that it must move like one. There is no way you can "guarantee" anything. The fact remains, reptiles live today and they are not the rulers of any terrain outside of the shallows and even then they are bullied by hippos. I understand evolution has a lot to do with the atmospheric conditions. Hence why crocs where able to live for so long. While the ice age happened or meteorites struck, the water based reptiles where able to retreat to the sea when the land was uninhabitable, they could slow their metabolism down and not have to eat for long periods of time. But, if reptiles could dominant today they would, But they cannot so they don't. You say "over-generalization" but if anything you are trying to make this animal into something it is not. Reptile or not, dinosaur or not, it doesn't matter. If you look at it from a anatomical perspective you can see that it would be severely out matched in terms of speed and agility against any large predatory mammal. |
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Post by Infinity Blade on Apr 4, 2014 1:25:46 GMT 5
"There's a reason the land is now ruled by mammals". Yeah, the K-Pg extinction event! Take that out of the equation and I can almost guarantee you that reptiles would still be the most dominant vertebrate clade on the planet. I remember something saying something like "evolution is not a process from good to better. Evolution is a process from doing well in this environment, to doing well in that environment". Evolution is not an argument. As for movement, the head and body balancing one end, the tail balancing the other. Is it so difficult to visualize that? Whether or not it will move or turn as fast as a tiger is not the thing here. In fact, I have absolutely no problem believing the tiger will be superior in this regard. What I have a problem with is the over-generalization that because it must be a reptile we're familiar with, that it must move like one. There is no way you can "guarantee" anything. The fact remains, reptiles live today and they are not the rulers of any terrain outside of the shallows and even then they are bullied by hippos. I understand evolution has a lot to do with the atmospheric conditions. Hence why crocs where able to live for so long. While the ice age happened or meteorites struck, the water based reptiles where able to retreat to the sea when the land was uninhabitable, they could slow their metabolism down and not have to eat for long periods of time. But, if reptiles could dominant today they would, But they cannot so they don't. You say "over-generalization" but if anything you are trying to make this animal into something it is not. Reptile or not, dinosaur or not, it doesn't matter. If you look at it from a anatomical perspective you can see that it would be severely out matched in terms of speed and agility against any large predatory mammal. I'm talking a HYPOTHETICAL SCENARIO, where the event doesn't happen. Most likely (and note how I even said " almost guarantee") they would still be the dominant vertebrate clade if it didn't happen. I know very well who's the dominant vertebrate clade in real life nowadays. Once again, I have ABSOLUTELY NO ISSUE BELIEVING THE TIGER IS MORE FASTER AND MORE AGILE. But Postosuchus is not "slow and unagile" or severely outmatched in those regards in the manner of modern reptiles as you suggest, almost certainly not even close. You really only need to look at its anatomy to figure it out. So, yes, there kind of is an over-generalization here. |
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pckts
Junior Member
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Post by pckts on Apr 4, 2014 1:27:03 GMT 5
Alright, I just did some research on Rauisuchian's.
So their closet relative is the croc, they have a erect gait with downward facing hip sockets which the femur sits directly underneath.
The postosuchus forelimbs are 64% of the hind limbs which would most likely make it bipedal or even facultative biped. Reading about where they most likely inhabited "lakes, uplands, warm and moist areas" I think it is shorter forelimbs because it would launch attacks hidden low ground and would launch up towards the high ground which could be why its forelimbs needed to be shorter than its hind limbs. Like a croc strike from water to land.
I am new to dinosaurs or Rauishuchians etc... It is interesting reading about these guys though.
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pckts
Junior Member
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Post by pckts on Apr 4, 2014 1:32:03 GMT 5
There is no way you can "guarantee" anything. The fact remains, reptiles live today and they are not the rulers of any terrain outside of the shallows and even then they are bullied by hippos. I understand evolution has a lot to do with the atmospheric conditions. Hence why crocs where able to live for so long. While the ice age happened or meteorites struck, the water based reptiles where able to retreat to the sea when the land was uninhabitable, they could slow their metabolism down and not have to eat for long periods of time. But, if reptiles could dominant today they would, But they cannot so they don't. You say "over-generalization" but if anything you are trying to make this animal into something it is not. Reptile or not, dinosaur or not, it doesn't matter. If you look at it from a anatomical perspective you can see that it would be severely out matched in terms of speed and agility against any large predatory mammal. I'm talking a HYPOTHETICAL SCENARIO, where the event doesn't happen. Most likely (and note how I even said " almost guarantee") they would still be the dominant vertebrate clade if it didn't happen. I know very well who's the dominant vertebrate clade in real life nowadays. Once again, I have ABSOLUTELY NO ISSUE BELIEVING THE TIGER IS MORE FASTER AND MORE AGILE. But Postosuchus is not "slow and unagile" or severely outmatched in those regards in the manner of modern reptiles as you suggest, almost certainly not even close. You really only need to look at its anatomy to figure it out. So, yes, there kind of is an over-generalization here. they would have no chance of dominating today, and they where soon replaced by much larger therapods after their extinction. Lastly they make mention to it most likely hunting smaller animals than itself, compared to a tiger which regularly preys on animals double or triple their own size. Another advantage of predatory mammals, they are much more equipped to take on animals larger than themselves. The agility and speed which they possess allows them to do so, which is why I keep on mentioning it. |
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Post by creature386 on Apr 4, 2014 1:37:27 GMT 5
Because you want to learn about them, have you read the book page I have linked?
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Post by Infinity Blade on Apr 4, 2014 1:39:03 GMT 5
I'm talking a HYPOTHETICAL SCENARIO, where the event doesn't happen. Most likely (and note how I even said " almost guarantee") they would still be the dominant vertebrate clade if it didn't happen. I know very well who's the dominant vertebrate clade in real life nowadays. Once again, I have ABSOLUTELY NO ISSUE BELIEVING THE TIGER IS MORE FASTER AND MORE AGILE. But Postosuchus is not "slow and unagile" or severely outmatched in those regards in the manner of modern reptiles as you suggest, almost certainly not even close. You really only need to look at its anatomy to figure it out. So, yes, there kind of is an over-generalization here. they would have no chance of dominating today, and they where soon replaced by much larger therapods after their extinction. Lastly they make mention to it most likely hunting smaller animals than itself, compared to a tiger which regularly preys on animals double or triple their own size. Another advantage of predatory mammals, they are much more equipped to take on animals larger than themselves. The agility and speed which they possess allows them to do so, which is why I keep on mentioning it. Yeah I understand pretty much everything here. They wouldn't have a chance of dominating, mostly because they didn't even live to see the K-T extinction! As for prey, I thought they had the option of hunting large synapsids (particularly dicynodonts). Those guys were around 1 or 2 tonnes. |
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pckts
Junior Member
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Post by pckts on Apr 4, 2014 1:47:37 GMT 5
How would a 250-300kg animal take down a 2 ton animal?
Lets be realistic.
Unless they hunted in packs there is no way that this animal could do it. They don't even have the forelimbs required to hang on and rip away at the hide of a larger animal. This animal would have to bite, shake and hold. It would be like watching a croc attack a adult elephant, rhino, cape buffalo or hippo. They don't have the limb strength required to tug of war a large animal. Watch Raja take down a gaur double his size. Once clamped on the Gaurs neck, raja uses his massive forelimbs to pull back and force the gaur to keep its hooves planted in the tug of war until its to late. A croc doesn't have that luxury.
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