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Saurophaganax maximus v Tyrannosaurus rex
Topic Started: Dec 15 2012, 10:02 PM (59,209 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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blaze
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@theropod
Anyway, Ray's estimate is from the time 15m for Tyrannosaurus was a good estimate along with 12m for a large Allosaurus and theropods were still reconstructed in tripod pose, NO ONE now should take seriously any estimates from that time.

And graphical scaling is not that bad as you say, I'll give you the measurements I got for some of Hartman's skeletals.

CM84 = 26.5m (published estimates: 24.7m and 26.3m)
CM1830 = 23.7m (published estimates: 21.0m, 22.8m)
HMNSII = 22.5m (published estimates: 21.8m, 22.5m)
MUCPv-Ch1 = 12.2m (published estimates: old=12.5m, updated=12.2m)
DINO2560 = 8.6m (published estimate = 8.5m, unpublished =7.9m)
FMNH PR2081 = 12.8m12.5m (published estimates = 12.3m, 12,8m)

I'm not seeing the "smaller" pattern you claim, if only the one for Big Al which IIRC was 7.1m, lower than the 8m floating in the web which I think are not actually published and given its bone measurements, 8m makes no sense.

I've told you why I believe scaling from a big armed Allosaurus makes more sense, and you're ignoring that even if the measurements I got of DINO 2560's humerus from Hartman's skeletal are wrong, the Hinkle allosaurus has a humerus one cm longer and is DINO sized given the size of its skull. I respect that you choose to ignore this and also ignore that Chilantaisaurus is also a large big armed allosauroid and use millions of years older Allosaurus specimens to scale so you get a bigger animal, I accept my estimate is conservative when compared to those 13m figures, but it's not conservative just for the sake of it, it's the most sensible approach and the one that requires the less evolutionary steps, don't act like your opinion is more reasonable, both are probable.
Edited by blaze, Dec 16 2012, 02:48 PM.
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Black Ice
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Quote:
 
gape isn't a much better advantage than B-vision.

How is B-Vision even an advantage?
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Jinfengopteryx
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Black Ice
Dec 16 2012, 05:57 AM
Quote:
 
gape isn't a much better advantage than B-vision.

How is B-Vision even an advantage?
Like that you don't miss that often. It doesn't change a lot, in a face to face fight it is quite worthless, but gape neither helps a lot, as both can bite the other and kill it, so gape would too just be helpful for not missing that often.
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Carcharadon
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Jinfengopteryx
Dec 16 2012, 05:40 AM
gape isn't a much better advantage than B-vision.

Oh please, binocular vision is absolutely no relevant advantage in a fight. Rhinos have poor vision but arent they good fighters? Gape often helps, sometimes it allows you to open your jaws wide enough to sink them into thick flesh thats too wide for other predators to bite into.

Jinfengopteryx
Dec 16 2012, 05:40 AM
Bite force doesn't matter at all? When tooth types aren't compareable, bite force won't be very important, but here their tooth are compareable (both are similar in shape and rely on serrations). Also, using comparisions, I could say gape is unimportant, because Tigers don't need an as wide gape as sharks, or claws are unimportant, because hyena don't need them.

Sure, bite force isn't absolutely needed, but it is an advantage.
I didn't say bite force doesn't matter at all. did you even read my post?
Edited by Carcharadon, Dec 16 2012, 06:17 AM.
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dino-ken
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Ok this is what REALLY pisses me off the most. Allosaurids are NOT POOR FIGHTERS AT ALL, PERIOD!!!!

They are good fighters really. They pack a flesh cutting bite, have a huge gape, and some have hatchet bite function (now please don't tell me this is irrelevant)


First - I agree that allosaurs and their kin were good fighters. After all they had to be since they mainly specialized in killing Sauropods. But generally Sauropods were slow moving, very large and hard to bring down.

It's just that Allosaurids are a very different kind of fighter and predator than Tyrannosaurs are. The Tyrannosaurine Tyrannosaurs like T.rex, are mainly Hadrosaur and Ceratopsian killers. They hunt powerful and dangerous prey that is capable of either running away (Hadrosaurs) or standing their ground and fighting (Ceratopsians).

The Allosaurs and the Carcharodontosaurs are designed to use a basic slash and dash type strikes. Basically run in, take a bite out of their prey and then move off to a save distance and wait for their prey to weaken down.

Big Tyrannosaurine Tyrannosaurs like T.rex are design for the quick ambush strike - similar to that of the modern Great White Shark. Basicially to seriously cripple or kill their prey in the first strike.

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theropod
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blaze
Dec 16 2012, 05:50 AM
@theropod
Anyway, Ray's estimate is from the time 15m for Tyrannosaurus was a good estimate along with 12m for a large Allosaurus and theropods were still reconstructed in tripod pose, NO ONE now should take seriously any estimates from that time.

And graphical scaling is not that bad as you say, I'll give you the measurements I got for some of Hartman's skeletals.

CM84 = 26.5m (published estimates: 24.7m and 26.3m)
CM1830 = 23.7m (published estimates: 21.0m, 22.8m)
HMNSII = 22.5m (published estimates: 21.8m, 22.5m)
MUCPv-Ch1 = 12.2m (published estimates: old=12.5m, updated=12.2m)
DINO2560 = 8.6m (published estimate = 8.5m, unpublished =7.9m)
FMNH PR2081 = 12.8m (published estimates = 12.3m, 12,8m)

I'm not seeing the "smaller" pattern you claim, if only the one for Big Al which IIRC was 7.1m, lower than the 8m floating in the web which I think are not actually published and given its bone measurements, 8m makes no sense.

I've told you why I believe scaling from a big armed Allosaurus makes more sense, and you're ignoring that even if the measurements I got of DINO 2560's humerus from Hartman's skeletal are wrong, the Hinkle allosaurus has a humerus one cm longer and is DINO sized given the size of its skull. I respect that you choose to ignore this and also ignore that Chilantaisaurus is also a large big armed allosauroid and use millions of years older Allosaurus specimens to scale so you get a bigger animal, I accept my estimate is conservative when compared to those 13m figures, but it's not conservative just for the sake of it, it's the most sensible approach and the one that requires the less evolutionary steps, don't act like your opinion is more reasonable, both are probable.
I didn´t claim it was, but it´s too conservative for my taste.

Really? I once scaled Sue to femur size using Hartmans skeletal and it was barely 11m long. Greg Paul also has a Sue skeletal that was posted here somewhere (by a member who wanted to show his weight estimate isn´t necessarily correct I think) which is only about 10m long based on scalebar.
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bone crusher
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Guess what Theropod I was right all along. A 12m T Rex is still bulkier and thus heavier than a 15m Saurophaganax if scaling up from an Allosaurus.
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People still underestimate how bulky and heavily built a robust morph T Rex was, it's pretty clear Sauro is like a 60kg leopard next to a 90kg Jaguar T .Rex.
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SpinoInWonderland
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Inaccurate and biased size comparison, use Scott Hartman's skeletals instead...

Greg Pauls' robust Tyrannosaurus is too robust, compare it with Hartman's Tyrannosaurus and you'll see...
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bone crusher
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Hartman's drawing still shows bigger skull, neck, calves in Sue. The T Rex would also be wider on top view. In any case a 15m Sauro is not proven, if going that route I can easily use the UCMP specimen which would ruin any sauro's day.
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SpinoInWonderland
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A comparison between a 15-meter allosaur and a 12-meter Tyrannosaurus

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click image for a full-sized version

As you can see, the allosaur clearly dwarfs the Tyrannosaurus if we use Scott Hartman's skeletals
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SpinoInWonderland
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bone crusher
Dec 16 2012, 12:00 PM
Hartman's drawing still shows bigger skull, neck, calves in Sue. The T Rex would also be wider on top view. In any case a 15m Sauro is not proven, if going that route I can easily use the UCMP specimen which would ruin any sauro's day.
I don't think UCMP 137538 is as large as you guys think and I don't even think it's even a Tyrannosaurus at all...
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blaze
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theropod
Dec 16 2012, 08:56 AM
Really? I once scaled Sue to femur size using Hartmans skeletal and it was barely 11m long. Greg Paul also has a Sue skeletal that was posted here somewhere (by a member who wanted to show his weight estimate isn´t necessarily correct I think) which is only about 10m long based on scalebar.
If I remember that post well, the Greg Paul skeletal was measured from tip to tip disregarding the curves of the neck and tail.

EDIT: I was also getting it at barely 11m from tip to tip too when I was scaling it with the other, smaller measure of the femur, when Hartman put an scalebar I thought that his skeletal was off by 8% because of that but then I realized that the easiest way to scale bones in a skeletal was using greatest length, and that I wasn't using such figure (1.38m for Sue) I knew I was scaling it wrong, so I used the scalebar and the femur does come close to ~1.38m and the total length is 12.1m 12.0m from tip to tip and 12.85m 12.5m along the curves.

EDIT 2: damn it, It ends up at 12.5m along the curves, the 12.8 I got was because I measured a version I made of it with invisible background and it seems I also cut a bit of the scale bar, anyway, its still no shorter than the published 12.3m
Edited by blaze, Dec 16 2012, 02:47 PM.
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blaze
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Broly, you're using the subadult Big Al, among the oldest specimens, from the lower Morrison, it doesn't show the enlongated tail seen in later Allosaurus, of course it would end up bigger. bone crusher used Greg Paul skeletal of DINO 2560, if you used Hartman's DINO 2560 it wouldn't look much different from bone crusher size chart.
Edited by blaze, Dec 16 2012, 12:29 PM.
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MysteryMeat
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How the hell do you get a 15 meter Saurophaganax? Based on what?
Limb proportions indicate 11m individuals.
UCMP 137538 is not a Tyrannosaur? Really? What it is then?
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MysteryMeat
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blaze
Dec 16 2012, 05:15 AM
Jinfengopteryx
 
theropod
 
no-one here has access to the paper as far as I know, it´s from 1941 and was published in some sort of magazine...


blaze has:
http://carnivoraforum.com/single/?p=8425263&t=9782364
The paper that Palaeocritti gives as further reading and that I have is this one:
Chure, Daniel J. (1995). "A reassessment of the gigantic theropod Saurophagus maximus from the Morrison Formation (Upper Jurassic) of Oklahoma, USA". in A. Sun and Y. Wang (eds.). Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, Short Papers. Beijing: China Ocean Press. pp. 103–106.
theropod
 
I wonder were he got it from. It doesn´t seem to be available anywhere on the web, and all the data are contradictory

The one I have I got it from a nice Argentinian forum, and while it is true that no one here has Ray's magazine article, Chure certainly does as he references it on the paper that I have.

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Weight estimates based on femurs are all under, but consistently under.
So that composite hind limb of Saurophaganax shows an allosaur that weighs 60% of a T. rex.
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