Welcome Guest [Log In] [Register]
Welcome to Carnivora. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
Saurophaganax maximus v Tyrannosaurus rex
Topic Started: Dec 15 2012, 10:02 PM (59,196 Views)
DinosaurMichael
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
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.

Posted Image

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.

Posted Image
Edited by DinosaurMichael, Dec 15 2012, 10:02 PM.
Offline Profile Quote Post Goto Top
 
Replies:
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
blaze
Apr 21 2013, 06:31 AM
That's Gecko's, yes.

broly, that size chart from Hartman is from 2004, can't you see how much his skeletals have changed? the 9 tonne Sue is not fat, get over it. Explain to me then how Sue dwarfs a supposedly 8 tonne Sarcosuchus or a 6 tonne elephant? you claim Paul's reconstructions are anorexic yet you take an old estimate only 300 kg heavier and tout it as gospel; that's the equivalent of saying a 50kg guy is anorexic but an equally sized 52kg guy is in the prime of his physical condition.

btw, look at the Carcharodontosaurus vs Saurophaganax thread, even your preferred method to scale S. maximus only makes it some 11m long now.
If the humerus was really that short. That would be a pretty huge scalebar error.

The specimen isn't mentioned, is it?

And the Sarcosuchus it dwarfs definitely isn't 8t. 8t would be a 12m Sarcosuchus at least as bulky as a saltie. The one shown in the most recent scales here, in which it is really dwarfed, was far more big headed, but slender and had a pretty small body.

Hartman still replied 6t was an intermediate estimate when I asked him not too long ago. I don't know about the metod, still this means age is not the issue here.

btw just in theory, a guy who is 165cm in height and 50kg would have a BMI of 18,4, while with 52kg it would be 19,1. The difference is not large, but still it is the difference between underweight and normal weight.
Offline Profile Quote Post Goto Top
 
Fist of the North Shrimp
vá á orminum
[ *  *  *  *  * ]
I have serious boubt that the BMI is a good way to determine someone being over or underweight(or normal weight). Being over and underweight is a pretty subjective grouping.
Who determines it? Look who invented the BMI and what his expetise in biology was(I can tell you, he was interested in Anthropometry but mostly his work on that is centered on his mathematic skills(which were kinda good), but lacks biological observations.
(Small note, anorexic means an even lower BMI than 18,4, you need a value less than 17,5 among other criteria)
Now take a guy of 1.8 meters (about my actual height and about the average size where I live), he would weight 60 kgs to have a BMI of 18.5. This is still a nomal weight accordind the BMI, but far from the average healthy,not saying that this mustn´t be healthy, especially nowadays.
Now, iin more demanding enviroments with less comformt available, this entirely different. The same guy would not be considered in prime healthy if he was living in the Upper Palaeolithic.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
This was just an example, its not implying anything about normal human weights...

I think anorexic is mostly too strong a term to refer to Greg Paul's weight estimates, they are undoubtedly rather low tough. Still tons of the estimates commonly used are even lower, for example the scary 3t mapusaurus with the 1,3m femur, the same metod based on femur circumference would put sue at more than 400kg less than Paul's estimate, and it underestimates other theropods even more. And these are the estimates many people are using to compare other species to significantly higher estimates for T. rex...
6-7t is still a range supported by many experts and imo at least as possible as the higher 8t+ range.
Offline Profile Quote Post Goto Top
 
coherentsheaf
Member Avatar
Kleptoparasite
[ *  *  *  *  *  * ]
theropod
Apr 21 2013, 06:29 PM
btw just in theory, a guy who is 165cm in height and 50kg would have a BMI of 18,4, while with 52kg it would be 19,1. The difference is not large, but still it is the difference between underweight and normal weight.
The problem with the BMI comparison is that categories of BMI are only tools to categorize a continous reality - at the borders these differences become meaningless. For example suppose some 1.80m tall person weighs 59.9395 kg. This results in him or her having a BMI that is considered underweight. If this person gains a single gram the resulting weight would be 59.9405 kg and the BMI would be in the normal range. Of course a gram of body mass is completely irrelevant from any practical perspective it is just the human concept that categorizes these two weights differently. Similarily even two kg are not that big of difference in humans - usually I would not notice that small gains in my fellow beings.
Edited by coherentsheaf, Apr 21 2013, 10:15 PM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
Exactly, and broly is a human!
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
@theropod
The specimen is mentioned, I've already said it. That Sarcosuchus might be slender but the size of its body is fine according to Sereno's skeletal, and about the guy thing that's why I specified 50kg = anorexic, equally tall 52kg guy = prime.
Edited by blaze, Apr 21 2013, 11:27 PM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
Well, if the Sarcosuchus is more slender (I wasn't discussing how reliable this reconstruction is, that's really not my field of knowledge and after all it was done by Hartman) than a saltie, it will be at lenght parity lighter than one, hence not as heavy as an upscaled Crocodylus porosus. and wasn't that at best an 11m individual? The animal would have been well below the 6t mark, not 8t.

The only way Deinosuchus would exceed 8t would be if it was 12m long and at least as heavily built, if it was a metre shorter or so, and more lightly built, then it is dwarfed by sue, yes, but it is also by far not 8t.
Edited by theropod, Apr 21 2013, 11:24 PM.
Offline Profile Quote Post Goto Top
 
Fist of the North Shrimp
vá á orminum
[ *  *  *  *  * ]
theropod
Apr 21 2013, 09:56 PM
This was just an example, its not implying anything about normal human weights...

I think anorexic is mostly too strong a term to refer to Greg Paul's weight estimates, they are undoubtedly rather low tough. Still tons of the estimates commonly used are even lower, for example the scary 3t mapusaurus with the 1,3m femur, the same metod based on femur circumference would put sue at more than 400kg less than Paul's estimate, and it underestimates other theropods even more. And these are the estimates many people are using to compare other species to significantly higher estimates for T. rex...
6-7t is still a range supported by many experts and imo at least as possible as the higher 8t+ range.
Well broly said that they were anorexic, you are right that they are not that extreme but show some of the properties of anorexic persons like visible bones that naturally would be not so evident.
They are relics from a different time...


@Coherentsheaf: Thank you, your assesement is far than my words on subjectivity.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
@theropod
Sarcosuchus or Deinosuchus?
Edit:
Anyway an scalebar error like the one that seems to be present in Chure (1995) is not without precedents, the error (~12%) is pretty much the same as the skull of Giganotosuaurs in Coria & Salgado (1995), interesting coincidence that both papers are from the same year.
Edited by blaze, Apr 22 2013, 01:19 AM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
oops, misunderstanding. Guess I just read "dwarfed" and automatically tought of this image:
http://images.wikia.com/archosauria/images/b/b4/Deinosuchus_vs_Tyrannosaurus.png

Well, again, an 11m Sarcosuchus would have to be ~6t. It isn't dwarfed at all, even tough the T. rex seems significantly more voluminous from a lateral perspective. You have to keep in mind Sarcosuchus might be about 200kg/m³ denser (Sue's around 800kg/m³), at least if it, like most aquatic animals, is close to the density of water, and from the top it would very likely seem bigger.
https://beizha.blu.livefilestore.com/y1pnoYNlakB7Zn9yqJ-ubHedQGZyJEf2yCxzhdjWAOmA9Md9VVoHpYQL0SiXmPj8hp22__g13toqyr1TgFdVHMN3IuJ0UISyjVN/Rexsarco.jpg?psid=1
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
I need to update that image, that is the long legged old Hartman's Sue, scaled to 1.32m femur length, the new one will be considerably bigger. I still exaggerated by saying "dwarfed" though.

The Sarcosuchus is only ~11m because I made the tail smaller to be similar in size to the skeletal in Sereno et al. (2001) it was originally over 12m, snout-vent length is what Sereno claims for a Sarcosuchus based entirely on the Saltwater croc (I claimed something different before, I was wrong) meaning its body corresponds to a 12m+ saltwater croc despite the short tail, I could add the extra 60cm of tail it needs but there wont' be two tonnes there.

Posted Image

Update of another version I had, I removed the skeletal from Planet Dinosaur and only left Hartman's and Sereno's, you can imagine how big is Sarcosuchus in a lateral view though and no matter how you see it it's not more voluminous than Sue, Sue's ribcage is also in the 1.6-1.7m range in width. And again, Sarcosuchus is only ~11m because it has a short tail, add to that the effect of looking at it in a top view, from which we can't actually see the axial length; the size of the body proportional to the skull is based on how a 12.2m saltie would be.

It's pretty much a fact that Sarcosuchus was more dense but that won't make up for enough mass difference in order to make Sue 6 tonnes and the croc be 8 tonnes. We've already discussed this though.
Edited by blaze, Apr 22 2013, 02:51 AM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
Sarcosuchus is 25% denser, that's quite a lot. If Sarco was 8t, a T. rex with the same volume would be...6,4t! That means if that Sarcosuchus was 8t, it is still quite possible T. rex would be below 7t.

If that's not too much work, what about adding an upscaled saltie for comparison? And that skeletal is from PD?
Edited by theropod, Apr 22 2013, 04:22 AM.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
If they were the same volume, which they are not, Sue's clearly bigger.

The Sarcosuchus skeletal in lateral view from the size chart of mine you linked earlier is modified from the one that appears on PD :P I could add a 12m saltie but I have to find a good image of a saltie in lateral view first.

Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
yes, but not that much bigger, just a bit.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
Sue's torso is similarly wide and long but is twice as tall...

Anyway, do you have Sereno et al. (2001)? because I've been stating incorrect things...

Here is what it does say and I have the pdf open so I don't make mistakes again... I quote.

Quote:
 
18.Regressions of body length ( y) against head length (x) for G. gangeticus ( y 5 269.369 1 7.4x, r2 5 0.972) and C. porosus ( y5220.224 1 7.717x, r2 5 0.98) yield total body length estimates of 11.15 m and 12.15 m, respectively, for a skull length of 160 cm. Mean total body length equals 11.65 m (38 feet, 3 inches) (Fig. 4B).
...

22. Using linear equations for C. porosus (13), we estimated snout-vent length in S. imperator from skull length (160 cm, yielding 572 cm) and from total body length (11.65 m, yielding 570 cm). We used mean snout-vent length (571 cm), in turn, to estimate a body weight (bw) of 7.96 metric tons [log bw5 22.0894 1 3.2613 (log 571 cm)].


The 8 tonne weight estimate is for an hypothetical saltie with a snout-vent length of 5.71m and a saltie 11.65m in total length will also have a SVL pretty much equal, at 5.70m.

This is the scale you requested but with some changes, since I was wrong that the 8 tonnes was for an 12m+ saltie and is instead for a 11.65m one (with a 5.7m SVL) I scaled it based on SVL, the photo wasn't a perfect lateral view though.

Posted Image

On a side note, in a lateral view Sarcosuchus skull looks so small that I think Sereno's estimated body size is an overestimate mmm.
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
DealsFor.me - The best sales, coupons, and discounts for you
Go to Next Page
« Previous Topic · Dinosauria Interspecific Conflict · Next Topic »
Add Reply

Find this theme on Forum2Forum.net & ZNR exclusively.