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Post by creature386 on Mar 22, 2019 23:59:38 GMT 5
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Post by spartan on Mar 23, 2019 16:26:17 GMT 5
They estimate Scotty at 8870kg and Sue at 8462kg in the paper. I'm not sure about the 13m since they also say this:
"Whether or not a robust/gracile dichotomy exists among T. rex, these comparisons indicate that RSM P2523.8 was a large and robustly-proportioned individual, but likely with a shorter total hip-height and snout-vent length than other known specimens showing more elongate proportions."
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Post by theropod on Mar 23, 2019 18:34:03 GMT 5
I’ve got access, if someone wants the paper send me a PM.
There’s no 13 m figure in the paper, nor any other dimensional size estimate. Once more one has to wonder why people keep making up fictional size figures.
The femur is 12 mm longer than Sue’s (according to this measurement, it is shorter than the 134 cm femur length reported by Larson 2008), and other dimensions aren’t that exceptional, but the robusticity of the elements is, just marginally larger than Sue in most measurements. It probably was not or only marginally longer than sue, but perhaps slightly more massive, as indicated by its femur circumference and cross-section and the area of the vertebral centra.
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Post by elosha11 on Mar 23, 2019 18:58:11 GMT 5
Scotty has almost a 20,000 pound estimate. 10 tons. T-rex just keeps getting more and more impressive as research advances.
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Post by spartan on Mar 23, 2019 19:18:12 GMT 5
Well, going with the broader ribcage & broader tail reconstruction from Snively's paper Scotty would weigh 10180kg.
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Post by theropod on May 6, 2019 1:17:34 GMT 5
Copying this over here from Dinosauria101’s matchup.
The size of the frontal of Sauroniops (Cau et al. 2012) is similar the largest known specimens of Acrocanthosaurus (NCSM 14345 has frontals 191mm long vs 186mm in Sauroniops, additionally the frontal of Sauroniops is considerably wider and more massive, 135mm for a single frontal vs 214mm for both frontals combined in Acrocanthosaurus [Eddy & Clarke 2011]) and Carcharodontosaurus (SGM-DIN 1 has a very similar frontal size based on the figures in Sereno et al. 1996, and Sauroniops’ frontal fits its skull nicely when superimposed). And that’s not something some fanboy on the internet made up, the describers explicitely state its size is similar to the aforementioned Acrocanthosaurus and Carcharodontosaurus specimens as well as the holotype of Giganotosaurus, they even provide a rough total length estimate of 10-12m, and this assessment (Cau et al. 2013) is followed by other authors as well (Candeiro et al. 2018), and is reproducible, as I just demonstrated.
These similar-sized taxa are all at least ~12m long and 6-7t in mass, so it stands to reason that Sauroniops, as another carcharodontosaur with very similar skeletal dimensions, is in that same size range. Neither the original descriptions nor any subsequent published work, nor the direct comparison between the frontal and those of related taxa, seem to provide a shred of support for this animal being just 9m long, in fact with the very obvious point of the single known element being similar in size to 11.5-13.5m theropods, I don’t really understand how anything like conclusive support for this would be possible. Say frontals of a 9m theropod were also similar in size (not to say that that’s the case). Even then, that wouldn’t be evidence in favour of that size estimate, but evidence that its size can not be reliably determined based on just a frontal, which I tend to agree with anyway. That’s an important distinction.
So if anyone wants to suggest Sauroniops is best estimates at 8-9m, let alone have it widely accepted, as it apparently already is when looking at various visual comparisons I can find, may they please bring forth some evidence for this?
Just being based on a single 19cm frontal, it is of course very fragmentary. There’s certainly a good point to be made for not taking any size estimate too serious, but that is only an argument to not make any conclusions about its size at all, not an argument for accepting a lower, but totally baseless figure. If there’s any size figure we want to show it as, then that should be the best and most accurate.
Candeiro, C.R. dos A., Brusatte, S.L., Vidal, L. and Pereira, P.V.L.G. da C. 2018. Paleobiogeographic evolution and distribution of Carcharodontosauridae (Dinosauria, Theropoda) during the middle Cretaceous of North Africa. Papéis Avulsos de Zoologia 58.
Cau, A., Dalla Vecchia, F.M. and Fabbri, M. 2012. Evidence of a new carcharodontosaurid from the Upper Cretaceous of Morocco. Acta Palaeontologica Polonica 57 (3): 661–666.
Cau, A., Dalla Vecchia, F.M. and Fabbri, M. 2013. A thick-skulled theropod (Dinosauria, Saurischia) from the Upper Cretaceous of Morocco with implications for carcharodontosaurid cranial evolution. Cretaceous Research 40: 251–260.
Eddy, D.R. and Clarke, J.A. 2011. New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda). PLOS ONE 6 (3): e17932.
Sereno, P.C., Dutheil, D.B., Iarochene, M., Larsson, H.C., Lyon, G.H., Magwene, P.M., Sidor, C.A., Varricchio, D.J. and Wilson, J.A. 1996. Predatory dinosaurs from the Sahara and Late Cretaceous faunal differentiation. Science 272 (5264): 986–991.
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Post by dinosauria101 on May 6, 2019 1:47:08 GMT 5
^Glad I could (in a way) help
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Post by theropod on May 6, 2019 2:02:16 GMT 5
Hmm yeah I was well aware this estimate existed from some places on deviantart, what I didn’t know was that it has apparently become the default figure for many. It always sounded suspicious, but if someone somehow arrived at that figure that’s one thing, if it is supposed to supersede another one that’s a different matter and requires proper evidence. That just prompted me to reiterate the facts. Also, if there’s an easy way to prevent nonsensical matchups from flooding this board, then it’s pointing out when one combatant is 10 times the size of the other…
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Post by dinosauria101 on May 25, 2019 9:04:15 GMT 5
Does anyone know if the apparently 3 tonne individuals of Mapusaurus are actual adults or if they're immature? Judging from the skeletal made by Franoys, remains suggest the species could weigh nearly 7 tonnes and somewhat over 12 meters long ( link). Wikipedia itself has a specimen size comparison with one individual at that body length, but it still states that its body mass was ~3 tonnes. Just noticed this right now, and I'm guessing it was brought up by the (now deleted) straight tusked elephant vs Mapusaurus pack thread on Carnivora? Anyhow, back on topic, 2 things: 1: I think they were immature, but the most common in the bonebed to be interpreted as average. IIRC, the bonebed had individuals of all sizes, including juveniles, which the 10 meter, 3 ton specimens must've been. I believe there's also a few scraps (pubic shaft?) of a 14 meter, 8+ ton individual, so I think we can stick with 12-12.5 meters and 7 tons as a reasonable adult average 2: Anyone know the true size of Zhuchengtyrannus? My secret source (message me if you'd like to know what it is) seems to state it was no larger than a big Daspletosaurus, but I've seen several other estimates well into T rex size territory. Which one would hold more water? |
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Post by Grey on May 25, 2019 15:02:48 GMT 5
Apparently several isolated Zhuchengtyrannus vertebra indicate T. rex size range.
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Post by Verdugo on Oct 22, 2019 16:42:11 GMT 5
The material consists of a coracoid, axis and neural arch of the presumed first dorsal vertebra. There is also a moderate-sized mid-cervical centrum, excluded from further analysis as it does not belong to an exceptionately large individual, and hence likely not the same animal as the rest of the remains. The original measurements as given are a preserved height of 290 mm and width of 400 mm and width of the neural spine of 83 mm for the dorsal neural arch (Cope 1878), a height of the axis of 250 mm (Chure 2000) and a coracoid length of ~380 mm (figure measurement from Osborn & Mook 1921, using dorsal neural arch for scale). It's all good but i just have some questions with this part. Are those figures given/stated/listed in the sources or merely obtained from using scale bars? |
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Post by theropod on Oct 22, 2019 19:12:11 GMT 5
Verdugo post moved here. Only the coracoid length is measured from a figure (back then, scalebars weren’t all the rage yet, I used the other figures with known measurements, shown at the same scale, as a stand-in for that), the others are all explicitly stated measurements.
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Post by dinosauria101 on Oct 25, 2019 1:29:19 GMT 5
Now, theropod, here's how I got 12.4 meters and 7 tons average for Mapusaurus. Anything under that in the bonebed seems not to be quite fully grown, and MCF-PVPH-108.145, the 13.6 meter specimen, seems to be a larger animal seeing as there is only 1 of it. Everything between those size ranges was fully grown and the majority of the mature specimens, so it falls in line with the paleontologist rule of thumb of a most common thing being the average. Most websites also seem to give a similar size range for average and maximum. |
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Post by theropod on Oct 25, 2019 1:40:18 GMT 5
Almost no theropod specimen is quite fully grown. There are maybe a few Allosaurus specimens, and two of Tyrannosaurus, that’s pretty much it. I would in fact have severe doubts that a 7 t Mapusaurus was fully grown, the odds are clearly against it, but the average adult size for a theropod doesn’t just include fully grown specimens, it includes all sexually mature specimens.
In which case (given that was what you meant), citation? I’d like to see if you have at least looked at actual evidence for the state of maturity of the specimens
Given that that material doesn’t belong to the same individual as the other material of very large Mapusaurus individuals from the bonebed, which is certainly possible, though hard to verify.
Again, what is your reference for which specimens are mature and which aren’t?
Isn’t the exact problem that most websites cite the estimated 10.3 m specimen as though it were maximum?
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Post by dinosauria101 on Oct 25, 2019 1:58:05 GMT 5
1: Almost no theropod specimen is quite fully grown. There are maybe a few Allosaurus specimens, and two of Tyrannosaurus, that’s pretty much it. I would in fact have severe doubts that a 7 t Mapusaurus was fully grown, the odds are clearly against it, but the average adult size for a theropod doesn’t just include fully grown specimens, it includes all sexually mature specimens. In which case (given that was what you meant), citation? I’d like to see if you have at least looked at actual evidence for the state of maturity of the specimens .2: Again, what is your reference for which specimens are mature and which aren’t? 3: Isn’t the exact problem that most websites cite the estimated 10.3 m specimen as though it were maximum? 1: I in fact looked at your Mapusaurus deviation and the comments below it: www.deviantart.com/theropod1/art/Another-368986042'I don’t know, not sure whether anybody really does, since we’ve got only a lower-bound estimate of the number of individuals to begin with. We know they include various ontogenetic stages and that there are at least 9 individuals in total, but it could conceivably be more than that and I don’t know which ones of the minimum number are adults. Based on the size distribution and the age distribution in other carnosaur bonebeds, I’d say it’s likely that the majority are immature.' Based on that, it seems only the 3 largest were the adults. But, you do have a point that they could be immature too. 2: That was based on your deviation and the comments too. Franoys and NamDaoTetanurae's are consistent with that too. 3: Er, sorry. That's a bit of an error on my part. Nowadays, I see most people relying on the description paper and Deviantart as opposed to the many random dino websites on the internet, and both are consistent with 12.4-13.6 meters as an average/max size. Though I do think it's interesting that they could be immature too. |
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