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Saurophaganax maximus v Tyrannosaurus rex
Topic Started: Dec 15 2012, 10:02 PM (59,190 Views)
DinosaurMichael
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Saurophaganax maximus
Saurophaganax ("lizard-eating master") is a genus of allosaurid dinosaur from the Morrison Formation of Late Jurassic Oklahoma (latest Kimmeridgian age, about 151 million years ago). Some paleontologists consider it to be a species of Allosaurus (A. maximus). Saurophaganax represents a very large (13 metres (43 ft) long). Saurophaganax was one of the largest carnivores of Late Jurassic North America. Ray even gave an estimate of the body length of fifteen metres and Chure of fourteen, though later estimations have been lower. The fossils known of Saurophaganax (both the possible New Mexican material and the Oklahoma material) are known from the latest part of the Morrison formation, suggesting that they were either always uncommon or appeared rather late in the fossil record. Saurophaganax was large for an allosaurid, and bigger than both its contemporaries Torvosaurus tanneri and Allosaurus fragilis. Being much rarer than its contemporaries, making up one percent or less of the Morrison theropod fauna, not much about its behavior is known. Stovall in Oklahoma also unearthed a considerable number of Apatosaurus specimens, a possible prey for a large theropod.

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Tyrannosaurus rex
Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 65.5 million years ago.[1] It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators. By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running in paleontology. Tyrannosaurus rex was one of the largest land carnivores of all time; the largest complete specimen, FMNH PR2081 ("Sue"), measured 12.8 metres (42 ft) long, and was 4.0 metres (13.1 ft) tall at the hips. Mass estimates have varied widely over the years, from more than 7.2 metric tons (7.9 short tons), to less than 4.5 metric tons (5.0 short tons), with most modern estimates ranging between 5.4 and 6.8 metric tons (6.0 and 7.5 short tons). Packard et al. (2009) tested dinosaur mass estimation procedures on elephants and concluded that dinosaur estimations are flawed and produce over-estimations; thus, the weight of Tyrannosaurus could be much less than usually estimated. Other estimations have concluded that the largest known Tyrannosaurus specimens had a weight exceeding 9 tonnes.

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Edited by DinosaurMichael, Dec 15 2012, 10:02 PM.
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theropod
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Of course, but allosauridae have a lighter built than carcharodontosauria, and Saurophaganax wasn't as long as C. saharicus.

Yes, more likely it would save weight than add it.

At best Saurophaganax at upper estimates is about equal to FMNH PR 2081, more likely sub-equal.
Edited by theropod, Jun 1 2013, 11:59 PM.
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SpinoInWonderland
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theropod
Jun 1 2013, 11:57 PM
Of course, but allosauridae have a lighter built than carcharodontosauria, and it wasn't as long as C. saharicus
And how massive do you suppose a ~13-meter carcharodontosaur is? I put the ~13.2-tonne Giganotosaurus at ~8 tonnes...
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theropod
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You mean the 13,2m one? Yeah, it might be close to 8t, maybe.
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SpinoInWonderland
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theropod
Jun 1 2013, 11:57 PM
more likely it would save weight than add it.
You must be crazy if you think Saurophaganax would be less massive than a scaled-up Allosaurus...No animal that ever lived gets less robust as it gets larger, I thought that you know about the square-cube law?
Edited by SpinoInWonderland, Jun 2 2013, 12:56 AM.
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Spinodontosaurus
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Yet by your own figures a scaled up Allosaurus is already heavier than a Tyrannosaurus?
brolyeuphyfusion
Jun 1 2013, 11:38 PM
Spinodontosaurus
Jun 1 2013, 04:35 AM
Even so, using it, UCMP 137538 or a speculative 'grown up' UCMP 118742 is no worse than Broly's selective gigantism bias towards Saurophaganax, except some of those Tyrannosaurus specimens are actually based on more than an incorrect scale bar and poor base models.
UCMP 118742 is already grown up and is just an average adult no larger than AMNH 5027, and don't even get started on the "mythical" UCMP 137538...

And poor base models? You're getting desperate.

I pretty much expected this kind of response... Instead of trying to 'disprove' these 'mythical' giant Tyrannosaurus', why don't you actually look at my point?
Your giant Saurophanagax is based on an inflated humerus stemming from incorrect scale bars and based on the worse of two potential base models. Why is this better than a correctly measured toe bone that, even using large-footed individuals, results in a huge total body size? Why is better than speculating how big an already huge young-adult could have got had it lived longer? Why is this worse than taking Horner's estimated size for Celeste? "Because it's just a guess, it could be wrong", well, your baseless estimate of Saurophaganax is demonstrably wrong!
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Teratophoneus
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When it comes to dinosaurs incomplete, I use to define the size of the maximum and the minimum estimate for the largest specimen.

example:

How big was Saurophaganax?
11-12.5/13 meters
How big was Mapusaurus?
12.2-14 meters
How big was Carcharodontosaurus?
11.1-14 meters

And so on ...

Since animals are incomplete, it is inuseless to look for a precise estimate.
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SpinoInWonderland
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Spinodontosaurus
Jun 2 2013, 01:40 AM
Yet by your own figures a scaled up Allosaurus is already heavier than a Tyrannosaurus?
brolyeuphyfusion
Jun 1 2013, 11:38 PM
Spinodontosaurus
Jun 1 2013, 04:35 AM
Even so, using it, UCMP 137538 or a speculative 'grown up' UCMP 118742 is no worse than Broly's selective gigantism bias towards Saurophaganax, except some of those Tyrannosaurus specimens are actually based on more than an incorrect scale bar and poor base models.
UCMP 118742 is already grown up and is just an average adult no larger than AMNH 5027, and don't even get started on the "mythical" UCMP 137538...

And poor base models? You're getting desperate.

I pretty much expected this kind of response... Instead of trying to 'disprove' these 'mythical' giant Tyrannosaurus', why don't you actually look at my point?
Your giant Saurophanagax is based on an inflated humerus stemming from incorrect scale bars and based on the worse of two potential base models. Why is this better than a correctly measured toe bone that, even using large-footed individuals, results in a huge total body size? Why is better than speculating how big an already huge young-adult could have got had it lived longer? Why is this worse than taking Horner's estimated size for Celeste? "Because it's just a guess, it could be wrong", well, your baseless estimate of Saurophaganax is demonstrably wrong!
You just can't stomach the idea of Jurassic theropods rivaling or exceeding the sizes of Cretaceous ones, can't you?

It makes more evolutionary sense that Jurassic theropods are larger, look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.

And my estimate is based on the humerus figure from the theropod database, it is not baseless...
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Spinodontosaurus
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brolyeuphyfusion
Jun 2 2013, 02:01 AM
You just can't stomach the idea of Jurassic theropods rivaling or exceeding the sizes of Cretaceous ones, can't you?

And the bias accusations begin... How hypocritical.
I honestly couldn't care less what time a dinosaur is from, but I do care about using the most realistic and accurate estimates.
If the most realistic and accurate size estimate of a Jurassic theropod puts it at a larger size than a cretaceous one, then so be it! Who cares?

[/color]
Quote:
 
It makes more evolutionary sense that Jurassic theropods are larger
...
And my estimate is based on the humerus figure from the theropod database, it is not baseless.

You are grasping at straws now, and being deliberately ignorant to boot. The humerus size has been thrown at you countless times, so I won't repeat it again.


Quote:
 
look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.

Really? Tell that to some of your carcharodontosaurids, as I don't think they got the message that supposed smaller prey in the cretaceous = smaller predators.
I don't think many titanosaurs got the message either.
Edited by Spinodontosaurus, Jun 2 2013, 02:18 AM.
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Teratophoneus
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brolyeuphyfusion
Jun 2 2013, 02:01 AM
Spinodontosaurus
Jun 2 2013, 01:40 AM
Yet by your own figures a scaled up Allosaurus is already heavier than a Tyrannosaurus?
brolyeuphyfusion
Jun 1 2013, 11:38 PM
Spinodontosaurus
Jun 1 2013, 04:35 AM
Even so, using it, UCMP 137538 or a speculative 'grown up' UCMP 118742 is no worse than Broly's selective gigantism bias towards Saurophaganax, except some of those Tyrannosaurus specimens are actually based on more than an incorrect scale bar and poor base models.
UCMP 118742 is already grown up and is just an average adult no larger than AMNH 5027, and don't even get started on the "mythical" UCMP 137538...

And poor base models? You're getting desperate.

I pretty much expected this kind of response... Instead of trying to 'disprove' these 'mythical' giant Tyrannosaurus', why don't you actually look at my point?
Your giant Saurophanagax is based on an inflated humerus stemming from incorrect scale bars and based on the worse of two potential base models. Why is this better than a correctly measured toe bone that, even using large-footed individuals, results in a huge total body size? Why is better than speculating how big an already huge young-adult could have got had it lived longer? Why is this worse than taking Horner's estimated size for Celeste? "Because it's just a guess, it could be wrong", well, your baseless estimate of Saurophaganax is demonstrably wrong!
You just can't stomach the idea of Jurassic theropods rivaling or exceeding the sizes of Cretaceous ones, can't you?

It makes more evolutionary sense that Jurassic theropods are larger, look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.

And my estimate is based on the humerus figure from the theropod database, it is not baseless...
Until proven otherwise, Tyrannosaurus, who lived with armored prey, was larger than Allosaurus, who lived with large sauropods.
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SpinoInWonderland
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Spinodontosaurus
Jun 2 2013, 02:18 AM
brolyeuphyfusion
Jun 2 2013, 02:01 AM
You just can't stomach the idea of Jurassic theropods rivaling or exceeding the sizes of Cretaceous ones, can't you?

And the bias accusations begin... How hypocritical.
I honestly couldn't care less what time a dinosaur is from, but I do care about using the most realistic and accurate estimates.
If the most realistic and accurate size estimate of a Jurassic theropod puts it at a larger size than a cretaceous one, then so be it! Who cares?
Apparently you, as you do everything to downsize Saurophaganax. And if you really didn't care, why did you start this long Saurophaganax size argument in the first place? Why not just have them at mass parity so this long and sensless size argument wouldn't have happened?

Spinodontosaurus
Jun 2 2013, 02:18 AM
Quote:
 
It makes more evolutionary sense that Jurassic theropods are larger
...
And my estimate is based on the humerus figure from the theropod database, it is not baseless.

You are grasping at straws now, and being deliberately ignorant to boot. The humerus size has been thrown at you countless times, so I won't repeat it again.
There is nothing ignorant there. If you actually looked through the known paleoecology of the Jurassic, there are strong reasons for Jurassic theropods to be larger.


Spinodontosaurus
Jun 2 2013, 02:18 AM
Quote:
 
look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.

Really? Tell that to some of your carcharodontosaurids, as I don't think they got the message that supposed smaller prey in the cretaceous = smaller predators.
I don't think many titanosaurs got the message either.
They were exceptions.

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SpinoInWonderland
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Dinosaur Planet
Jun 2 2013, 02:27 AM
brolyeuphyfusion
Jun 2 2013, 02:01 AM
Spinodontosaurus
Jun 2 2013, 01:40 AM
Yet by your own figures a scaled up Allosaurus is already heavier than a Tyrannosaurus?
brolyeuphyfusion
Jun 1 2013, 11:38 PM
Spinodontosaurus
Jun 1 2013, 04:35 AM
Even so, using it, UCMP 137538 or a speculative 'grown up' UCMP 118742 is no worse than Broly's selective gigantism bias towards Saurophaganax, except some of those Tyrannosaurus specimens are actually based on more than an incorrect scale bar and poor base models.
UCMP 118742 is already grown up and is just an average adult no larger than AMNH 5027, and don't even get started on the "mythical" UCMP 137538...

And poor base models? You're getting desperate.

I pretty much expected this kind of response... Instead of trying to 'disprove' these 'mythical' giant Tyrannosaurus', why don't you actually look at my point?
Your giant Saurophanagax is based on an inflated humerus stemming from incorrect scale bars and based on the worse of two potential base models. Why is this better than a correctly measured toe bone that, even using large-footed individuals, results in a huge total body size? Why is better than speculating how big an already huge young-adult could have got had it lived longer? Why is this worse than taking Horner's estimated size for Celeste? "Because it's just a guess, it could be wrong", well, your baseless estimate of Saurophaganax is demonstrably wrong!
You just can't stomach the idea of Jurassic theropods rivaling or exceeding the sizes of Cretaceous ones, can't you?

It makes more evolutionary sense that Jurassic theropods are larger, look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.

And my estimate is based on the humerus figure from the theropod database, it is not baseless...
Until proven otherwise, Tyrannosaurus, who lived with armored prey, was larger than Allosaurus, who lived with large sauropods.
Tyrannosaurus does not represent the rule of Cretaceous theropod size
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theropod
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We don't know which humerus figure is correct, you are making lots of baseless definitive assumptions (both of you)!
I don't see why Big Al or the Topotype should be worse models, I simply cannot see a reason. Because DINO is a bit bigger? That is certainly not a better base than preferring shorter arms because Saurophaganax is bigger and should follow theropod allometry. What estimate is more likely is a matter of personal consideration, but you are exagerating when making it seem like one was baseless.
btw Saurophaganax is also from the Kimmeridgian (theropod database/the dinosauria), the age difference, if there is one, is not relevant.

Inferring a predator's size from prey size is a very unscientific, speculative approach and should not be used either.

And all those tyrannosaurs are even worse, because there is little base at all. Since when can you confuse a humerus with at least 8 other humeri that would all result in different, mostly smaller estimates? And since when is a growth formula made up by a topix-fanboy and filled with inaccurate size figures better? Not to mention that if you use the growth argument, you'd first have to check how old some of the other giant theropods were when they died, to see whether they could too have potentially grown bigger. The on the field guess of Horner has little weight, unless including his 2,4m Spinosaurus skull which would arguably result in a 20m+ Spinosaurus.

This debate's really getting absurd.
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Tyrant
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Quote:
 
It makes more evolutionary sense that Jurassic theropods are larger, look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.



Modern day whales are larger than those during megalodons time period, therefore there must be some modern day sharks larger than it!
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SpinoInWonderland
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Tyrant
Jun 2 2013, 02:45 AM
Quote:
 
It makes more evolutionary sense that Jurassic theropods are larger, look man, there is a huge abundance of huge prey in the Jurassic, unlike in the Cretaceous, where smaller ornithopods are more common.



Modern day whales are larger than those during megalodons time period, therefore there must be some modern day sharks larger than it!
Megalodon became extinct just ~2 million years ago, the whale size was very likely similar to today's back then, and no modern shark has yet enough time to evolve to succeed Megalodon.
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Tyrant
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Quote:
 
Megalodon became extinct just ~2 million years ago, the whale size was very likely similar to today's back then, and no modern shark has yet enough time to evolve to succeed Megalodon.


My point was that you claim that Jurassic theropods are probably larger than Cretaceous ones because the former lived amongst larger fauna. With this logic modern day sharks would be larger than megalodon as modern day whales are far larger than those during megalodons time, yet none nearly even approach its size.

Until we actually have any reliable fossil evidence of a large Jurassic Park theropod bigger than Tyrannosaurus, spinosaurus and the like no one can really claim that Jurassic Park theropods were larger than those living in the Cretaceous.
Edited by Tyrant, Jun 2 2013, 02:53 AM.
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