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Giganotosaurus carolinii v Tyrannosaurus rex
Topic Started: Jan 31 2012, 05:48 PM (110,335 Views)
Taipan
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Giganotosaurus carolinii
Giganotosaurus ("giant southern lizard"), was a carcharodontosaurid dinosaur that lived 93 to 89 million years ago during the Turonian stage of the Late Cretaceous period. It is one of the longest known terrestrial carnivores, bigger than Tyrannosaurus, but in length and weight, smaller than Spinosaurus. Although longer than T. rex, G. carolinii was lighter and had a much smaller braincase that was the size and shape of a banana. A well-developed olfactory region means it probably had a good sense of smell. Titanosaur fossils have been recovered near the remains of Giganotosaurus, leading to speculation that these carnivores may have preyed on the giant herbivores. Fossils of related carcharodontosaurid fossils grouped closely together may indicate pack hunting, a behavior that could possibly extend to Giganotosaurus itself. he holotype specimen's (MUCPv-Ch1) skeleton was about 70% complete and included parts of the skull, a lower jaw, pelvis, hindlimbs and most of the backbone. The premaxillae, jugals, quadratojugals, the back of the lower jaws and the forelimbs are missing. Various estimates find that it measured somewhere between 12.2 and 13 m (40 and 43 ft) in length, and between 6.5 and 13.3 tons in weight. A second, more fragmentary, specimen (MUCPv-95) has also been identified, found in 1987 by Jorge Calvo. It is only known from the front part of the left dentary which is 8% larger than the equivalent bone from the holotype. This largest Giganotosaurus specimen is estimated to represent an individual with a skull length of 195 cm (6.40 ft), compared to the holotype's estimated at 1.80 m (5.9 ft) skull, making it likely that Giganotosaurus had the largest skull of any known theropod. Giganotosaurus surpassed Tyrannosaurus in mass by at least half a ton (the upper size estimate for T. rex is 9.1 t). Additionally several single teeth, discovered from 1987 onwards, have been referred to the species.

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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. 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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Prehistoric Cat
Jan 31 2012, 04:53 PM
Giganotosaurus VS Tyrannosaurus
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And I thought it was also heavier than Sue, but I guess you can't really give an accurate estimation if you only have a part of the dentary (other than that it had to be pretty big).
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bone crusher
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The fight result is really dependent on the individual we choose to use here, so here are the scenarios.

1. Best case scenario for both t Rex and Giga. Using the UCMP 137538 specimen and assuming linear size increase from a 20% larger pedal phalanx in relation to Sue's. We get a 14m+ T Rex that would weigh well over 12 tons. Against the MUCPv 95 Giganotosaurus specimen which Hartman has extracted the size based solely on that lower dental bone that is slightly deeper than the Holotype, so he gets a 13m Giga weighs 8200kg, stiller lower than his 8400kg estimate for Sue mind you. So that's the most ideal for both contenders, result? Overkill 85/15 in T Rex's favor.

2. Scenario based on most reliable and scientifically confirmed data. FMNH Sue the most complete T Rex specimen found "95% complete" at 8400kg using Scott Hartman's data vs Holotype MUCPv Ch1 Giga specimen about "70% complete" at 6800kg using Hartman's data. 70/30 to T Rex for much bigger weight advantage, bulkier and stronger.

3. Scenario for weight parity, almost. Sue at 8400kg vs a hypothetical MUCPv-95 in best case scenario 8200kg. 60/40 to T Rex, for being more muscled, bulkier and slightly heavier even at a shorter length, likely to end the fight faster with a well placed bone crushing bite. More durable due to more robust build and better 3d optical perception for more accurate strikes.

4. Scenario for T Rex at weight disadvantage. Say T Rex at 1000kg weight disadvantage, 50/50. The more robust build of T Rex should somehow alleviate the weight disadvantage, there' always a chance T rex could deliver that critical killer bite and end the fight sooner.

5. Scenario for T Rex at 1.5-2t weight disadvantage. 60/40 Giga for overwhelming weight advantage.

reference.
http://www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013
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theropod
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^Lol, you think a T. rex would win in 50% of cases with a 1t weight disadvantage?

Note that that’s about the right size difference on average. It’s around 50/50 at weight parity imo, even tough Giganotosaurus looks a bit more impressive because it is longer and taller.
Edited by theropod, Jun 9 2015, 06:43 PM.
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bone crusher
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What's on average? When did we get any meaningful data of the average weight and size for either animal through a handful of incomplete samples lol? Can you determine the average of Giga through a sample size of two individuals? Come on now. Also Sue is the only T Rex that has lived for 28 years thus explaining her heftier weight than a couple of other Rexes.
I can respect your opinion of 50/50 at weight parity even though I believe Rex still has more advantages. I would also back a 80kg jaguar against a 90kg leopard any day due to a more robust and bulkier built, same thing apply here.
Now look is subjective, yeah Giga might look more graceful for being more slender, less bulky but I prefer T Rex's look any day :). The new restoration from Hartman makes it even more compact, robust and tank like since it's shorter now. Same way as I find Brontosaurus more impressive than Diplodocus tho to a less extreme.
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theropod
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Quote:
 
What's on average?
~6.4t or slightly less for T. rex
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When did we get any meaningful data of the average weight and size for either animal through a handful of incomplete samples lol?
Matter of fact, we’ve had meaningful data nicely summed up in Larson 2008.
Posted Image
Let’s be generous by excluding the smallest, which, at 17 years of age could still be a subadult. That leaves us with a sample of 15 adult T. rex specimens (most of these confirmed by histological data, the others based on probability):
"sp""fl""fc"
"CM 9380"1200545
"MOR 1128"1260580
"MOR 1125"1150510
"MOR 555"1275514
"MOR 98O"1232483
"FMNH PR 2081"1340580
"BHI 3033"1310500
"BHI 6232"1180527
"BHI 6233"1110515
"BHI 6230"1190494
"BHI 6242"1180512
"RTMP 81.12.1"1200560
"RTMP 81.6.1"1210470
"LL12823"1200467
"Samson"1295560

Femur lengths range from 111cm to 134cm, with a mean of 122cm. Based on sue, an average total length of 11.2m and a body mass of 6.37t. That’s perhaps slightly too liberal considering that sue is unusually robust and that smaller specimens like Stan can have proportionately longer femora, but I’m fine with it for now (we wouldn’t want to underestimate T. rex’ size, would we?).

For those who prefer that, we can do the same for femur circumference and arrive at a length of 11.1m and a weight of 6.1t, but I think that isn’t more reliable than femur length, because it could be subject to similar or greater degrees of variation.

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Can you determine the average of Giga through a sample size of two individuals?
Yes, that is a mathematical operation that I could do when I was in primary school (at least if you let me have the calculator). It is of course subject to greater uncertainty, but what better option would you suggest to use? Comparing the largest individuals has all of the downsides but none of the improvements of what I’m doing here, and it is systematically biased against Giganotosaurus.
So based on Hartman 2013 that would be (12.4+13.2)/2=12.8m and (8.2+6.8)/2=7.5t

The data should make us careful, but they do exist and they suggest greater average size for Giganotosaurus, as well as that their comparable maximum sizes are an artifact of the carnosaur’s much smaller sample size.

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Also Sue is the only T Rex that has lived for 28 years thus explaining her heftier weight than a couple of other Rexes.
Precisely. Sue is exceptionally old, the probability of a random adult theropod being such an old and relatively large individual is very low. In Myhrvold’s (2013) analysis only 3 of the 14 studied dinosaur taxa were found to include osteologically mature individuals that had reached 90% or more of adult body size (and sue is likely very mature even among those). Likewise, Bypee et al. could not identify a single specimen of Allosaurus that had the same signs of osteological maturity that are present on sue (an external fundamental system, Erickson et al. 2004).

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I can respect your opinion of 50/50 at weight parity even though I believe Rex still has more advantages.
That’s nice to read. I can also respect your opinion, although I don’t agree with it and think it is disproportionately widespread considering the actual evidence.

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I would also back a 80kg jaguar against a 90kg leopard any day due to a more robust and bulkier built
Well, I wouldn’t, in direct confrontation between two macripredatory felines I would back the larger cat. Also I think leopard vs hyaena with a leapard that has a bit of a weight advantage is the better analogy. The hyaena is impressively robust, cursorial and has an exceptionally strong bite force, but ultimately greater size and the leopard’s other advantages will probably take the cake.

Giganotosaurus doesn’t have grappling ability on par with a leopard, but in exchange its bite is equally deadly (not like those of cats, which I’d consider inferior to similar-sized canids and hyaenids).

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Now look is subjective
Of course it is, I meant it as a warning. At equal weights Giganotosaurus may be the one that looks more impressive to some, but it’s still the same size, and similar in overall muscle mass and power. Similarly, T. rex may be the one that look more robust when looking at them individually, but at equal weights this has little actual value, slightly better durability due to the more robust shape, but that’s made up for by greater reach on the side of the carnosaur.

–––References:
Bypee, Paul J.; Lee, Andrew H.; Lamm, Ellen-Thérèse (2006): Sizing the Jurassic Theropod Dinosaur Allosaurus: Assessing Growth Strategy and Evolution of Ontogenetic Scaling of Limbs. Journal of Morphology, Vol. 267 pp. 347-359
Erickson, Gregory M.; Makovicky, Peter J.; Currie, Philip J.; Norell, Mark A.; Yerby, Scott A.; Brochu, Christopher A. (2004): Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature, Vol. 430 (7001) pp. 772-775
Larson, Peter (2008): Variation and Sexual Dimorphism in Tyrannosaurus rex. In: Larson, Peter; Carpenter, Kenneth: Tyrannosaurus rex the Tyrant King. Bloomington pp. 103-128
Myhrvold, Nathan P. (2013): Revisiting the Estimation of Dinosaur Growth Rates. PLoS ONE, Vol. 8 (12) pp. 1-24

Hartman, Scott (2013): Mass estimates: North vs South redux. http://www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013 (accessed 04 January 2015)
Edited by theropod, Jun 11 2015, 07:34 AM.
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bone crusher
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Do you honestly think a sample size of 15 adult Rexes of various age and sexes is any where close to determine the median weight of a fully grown robust morph T rex, much less the upper or lower bound? You may think statistically it's against Giga but in fact it's a double edged sword. What if those 14 other T Rexes are in the lower weight range to stat off with? It's also obvious to note non of them have lived to their full weight potential by being much younger or a gracile morph. Too much uncertainties and variables my friend to meaningfully determine the actual median weight without accessing to hundreds if not thousands more specimens, not to mention the possible huge geological subspecies variation. Same could be applied for Giga likewise of course, the TYPE specimen could well be the "Sue" of Giga while the other one could simply be a big jawed "MOR008".

The Point is you can't conveniently use the word average weight just yet, for Allosaurus maybe you can but not T Rex or Giga. We can only compare the individuals, not as species. Things we can compare species wise is the body proportion, weaponry and robustness, which T Rex is simply a much more robust, bulkier animal. As for longer reach vs robustness, you are way underestimating the importance of a more powerfully built organism vs a longer, taller organism of similar weight. In a fight tell me a 2m tall basketball player would win against a 1.94m wrestler. Sure Giga might land the first strike, but Rex could just hit back harder while receiving less damage, eventually Giga would tire out sooner and slow down its movement. T Rex could eventually brute force its way in and get the angle it wanted to deliver that killing bite.

As far as the fight goes based on most reliable and scientifically plausible data, T Rex wins simply because Sue, it's outright much heavier than the Type Giga as well as much more robust. It ain't anyone's fault we haven't found more giga specimens of reasonable completeness that is bigger than the holotype as a whole.

Also this is from someone in another forum who has comparisons based on Hartman's latest drawings and puts the T.rex size in perspective quite a bit.
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Edited by bone crusher, Jun 9 2015, 10:54 PM.
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bone crusher
Jun 9 2015, 10:01 PM
Do you honestly think a sample size of 15 adult Rexes of various age and sexes is any where close to determine the median weight of a fully grown robust morph T rex, much less the upper or lower bound?
We indeed do not have enough specimens. Also that chart is a pretty old one I did. I no longer feel confident about several aspects of it - take it with a grain of salt basically. The smallest specimen on there, Stan, is certainly not the smallest known adult. That prize goes to MOR 1125, a.k.a. 'Bob'.
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bone crusher
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Jun 9 2015, 11:32 PM
bone crusher
Jun 9 2015, 10:01 PM
Do you honestly think a sample size of 15 adult Rexes of various age and sexes is any where close to determine the median weight of a fully grown robust morph T rex, much less the upper or lower bound?
We indeed do not have enough specimens. Also that chart is a pretty old one I did. I no longer feel confident about several aspects of it - take it with a grain of salt basically. The smallest specimen on there, Stan, is certainly not the smallest known adult. That prize goes to MOR 1125, a.k.a. 'Bob'.
Ah cool so it's you :), anyway do you plan on making a new updated comparison soon?
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blaze
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I will be hesitant to call what Larson did a "morphometric analyses" and that's why "robust/gracile morph" doesn't really exist outside of his head.
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theropod
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@blaze: I’m not really interested in the robust/gracile-morph debate, it’s support seems weak and the arguments are sort of ideological by the seem of it. But the size data are real.

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Do you honestly think a sample size of 15 adult Rexes of various age and sexes is any where close to determine the median weight of a fully grown robust morph T rex, much less the upper or lower bound?
Do you honestly think a sample size of 2 Giganotosaurus of unknown age and state of maturity is enough to determine the maximum size? The answer is obviously: much less.
Why robust morph? It seems that you are intentionally picking out the biggest T. rex specimens to compare them top randomly selected individuals of Giganotosaurus.

And yes, I think these 15 T. rex specimens can give us an idea of its average size.

The question should be, do you have any evidence that it was larger or smaller than the numbers resulting from these data?

btw "fully grown" is an irrelevant concept, as I already outlined (but I’m happy to do it again) almost no theropod is known from fully grown specimens, including those as well-sampled as Allosaurus. What I am doing is comparing mature specimens, not fully grown ones. We are not likely to have found a fully grown Giganotosaurus yet, considering only one in over 50 T. reges is considered fully grown in your opinion. The tiny probability that we have is accounted for by likening our expected value to the average of a sample that includes FMNH PR 2081.

Most of these specimens are confirmed adults at 18 years of age or older (Erickson et al. 2006), the few to which this doesn’t apply are in a similar size range, larger than any subadult I know of and thus are probably adults too.

Quote:
 
You may think statistically it's against Giga but in fact it's a double edged sword. What if those 14 other T Rexes are in the lower weight range to stat off with?
That would be very unlikely, especially since several of them demonstrably aren’t.
Actually, if all of these were in the "lower weight range", then that simply wouldn’t be the lower weight range any more, but those that wouldn’t be in that weight range would be unusually big specimens. This is a relatively unbiased sample, unlike most that you can find (even seen a skeletal of MOR 1125, or MOR 009, or Wyrex? No, because they are less impressive than the big guys, such as sue. The smallest commonly depicted specimen is actually stan, which is relatively close to the average size).

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It's also obvious to note non of them have lived to their full weight potential by being much younger or a gracile morph.
Well, what about the only two known Giganotosaurus specimens having "lived their whole weight potential"? If the vast majority of adult T. rex or Allosaurus specimens haven’t (which is a fact), then how likely are we to have found two Giganotosaurus specimens that have in a sample of…2?

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Too much uncertainties and variables my friend to meaningfully determine the actual median weight without accessing to hundreds if not thousands more specimens, not to mention the possible huge geological subspecies variation.
Literally everything you say applies to maximum weights even more. But there’s no systematic bias when determining average sizes, while there is when determining maximum size, so I will go with the average size as the one that is less biased and at best similarly error-prone, if not less.

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Same could be applied for Giga likewise of course, the TYPE specimen could well be the "Sue" of Giga while the other one could simply be a big jawed "MOR008".
It’s equally likely that it’s the MOR 1125 of Giganotosaurus.
And MOR 008 has a considerably smaller jaw than Sue so the analogy just doesn’t work.

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he Point is you can't conveniently use the word average weight just yet, for Allosaurus maybe you can
I don’t have a data set of 15 adult Allosaurus femora, do you? At Cleveland Lloyd over 80% of Allosaurus specimens are subadults or juveniles (Gates 2005), and Bypee et al. 2006 were not able to find a specimen in which osteological maturity of the level of Sue.
Yet I do indeed prefer to go with the data that we have on Allosaurus and conclude that an average specimen is between 8 and 9m, most likely close to the length of DINO 2560 (~8.5m).

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We can only compare the individuals, not as species.
Then I guess we’d best leave the thread and make something the likes of "T. rex specimen SOMEMUSEUMABBREVIATION number vs giganotosaurus MUCPv-ch1 or -95"
I’m not interested in what some think we can’t, I’m interested in doing as best we can with what we have.

So who sais that of all T. rex specimens we use sue, without even so much as trying to use a moderate-sized specimen?

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In a fight tell me a 2m tall basketball player would win against a 1.94m wrestler.
He wouldn’t, but not because he’s longer/taller, but because he’s not a fighter. Giganotosaurus on the other hand may be a bit less compact in built, but it’s still a macropredator perfectly adapted for killing dangerous animals, with an evidently potent bite and great physical strength.
And this isn’t a wrestling match either. if both would wrestle each other, maybe robustness would matter more, but it just isn’t, neither of them can really wrestle (though if either can it is Giganotosaurus due to its more flexible spine and functional forelimbs).

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Sure Giga might land the first strike, but Rex could just hit back harder while receiving less damage, eventually Giga would tire out sooner and slow down its movement.
How is that?
There is no way a single well-placed bite by Giganotosaurus won’t kill or effectively incapacitate it near-instantly, just like the reverse of course.

Quote:
 
As far as the fight goes based on most reliable and scientifically plausible data, T Rex wins simply because Sue, it's outright much heavier than the Type Giga as well as much more robust. It ain't anyone's fault we haven't found more giga specimens of reasonable completeness that is bigger than the holotype as a whole.
It certainly isn’t the fault of Giganotosaurus either.

–––References:
Bypee, Paul J.; Lee, Andrew H.; Lamm, Ellen-Thérèse (2006): Sizing the Jurassic Theropod Dinosaur Allosaurus: Assessing Growth Strategy and Evolution of Ontogenetic Scaling of Limbs. Journal of Morphology, Vol. 267 pp. 347-359
Erickson, Gregory M.; Currie, Philip J.; Inouye, Brian D.; Winn, Alice A. (2006): Tyrannosaur Life Tables: An Example of Nonavian Dinosaur Population Biology. Science, Vol. 313 (5784) pp. 213-217
Erickson, Gregory M.; Makovicky, Peter J.; Currie, Philip J.; Norell, Mark A.; Yerby, Scott A.; Brochu, Christopher A. (2004): Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature, Vol. 430 (7001) pp. 772-775
Edited by theropod, Jun 10 2015, 03:46 AM.
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blaze
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@theropod
I didn't meant to say that you did, I was just disagreeing with calling it that and the next part of the comment was more directed at bone crusher but I wasn't very clear.
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theropod
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^You’re right anyway, it wasn’t very rigorously analysed (but that’s not why I like the chapter, it simply contains some valuable measurements and one of the few larger, uniform samples thereof). Anyway I think this sample should suffice for something as simple as gaining an idea of the average size.
Edited by theropod, Jun 10 2015, 03:13 AM.
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SpinoInWonderland
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theropod
Jun 10 2015, 12:58 AM
comparing mature specimens, not fully grown ones
Isn't "fully grown" just another term for skeletal maturity when referring to dinosaurs?
Edited by SpinoInWonderland, Jun 10 2015, 03:17 AM.
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Spartan
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How are Tyrannosaurus' forelimbs not functional? They are just very short. (Not that their arms would matter much in a fight anyway)
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theropod
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^Sorry. I meant "not functional for fighting purposes". They are of course fully functional as an aid in getting up from a sitting position or potentially as mating claspers.

@spino in wonderland: The question is what you consider to be skeletally mature. Fully grown has a very clear, obvious meaning and I’d suggest keeping it. When I say fully grown I mean close to maximum attainable size up to a negligible amount (e.g. sue), which applies to very few adult theropods.
Osteological maturity on the other hand is always relative, and its signs aren’t always obvious. But generally, if something is an actual juvenile or subadult (those animals still in a phase of exponential or at least very fast growth), that’s probably relatively obvious. less so for adults with a slowed, but still noticeably amount of growth going on (e.g. the majority of T. rex specimens)
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