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Post by creature386 on Jun 4, 2015 19:26:29 GMT 5
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Post by Deleted on Jun 4, 2015 20:07:02 GMT 5
Wow that kneck looks almost cartoonishly massive! A size comparison showing the possible size of the owner of the giant 2014 Argentinian titanosaur femur:  That Apatosaurus looks awfully puny, and it's already a large sauropod in itself! Apatosaurus louisae and Argentinian titanosaur(based on Futalognkosaurus) reconstructions from Scott Hartman. Yeah, it's huge! I measured it's axial length and it ended up at around ~31.64 meters. The A. louisae should be around ~23ish meters long give or take. |
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Post by spinodontosaurus on Jun 4, 2015 20:50:41 GMT 5
Wow that kneck looks almost cartoonishly massive! Large titanosaurs generally have massive necks, Alamosaurus is a good example of this. As of course so is Futalognkosaurus, which is the skeletal Broly used in that chart. Well, sort of, because Broly seems to have used a slightly older version of the skeletal (?), the new one has an even thicker neck. You can see how Futalognkosaurus stacks up against Alamosaurus and other giants in this great chart that Scott Hartman put together: img14.deviantart.net/8d2b/i/2015/111/6/2/thunder_lizard_size_comparison_by_scotthartman-d6909lc.jpgThe unnamed Argentinian giant is probably about as big as the large Alamosaurus on that chart btw. |
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Post by Deleted on Jun 5, 2015 0:39:39 GMT 5
Wow that kneck looks almost cartoonishly massive! Large titanosaurs generally have massive necks, Alamosaurus is a good example of this. As of course so is Futalognkosaurus, which is the skeletal Broly used in that chart. Well, sort of, because Broly seems to have used a slightly older version of the skeletal (?), the new one has an even thicker neck. A very slight difference in the depth of the neck base doesn't really make any actual relevant difference. Anyway, I measured the axial length of Scott Hartman's Futalognkosaurus and it ends up at ~21.53 meters long. If this Futalognkosaurus had a mass of ~30 tonnes in life, the giant Argentinian titanosaur would end up at ~95.21 tonnes. Using Zach's mass estimates(~23.7-25.6 tonnes) for Futalognkosaurus gives a range of ~75.2-81.2 tonnes, but Zach's Futalognkosaurus seems a bit...malnourished...compared to Scott Hartman's Futalognkosaurus. |
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Post by spinodontosaurus on Jun 5, 2015 1:36:01 GMT 5
^That compares to Armstrong estimating the largest Alamosaurus at 74 tonnes, and Argentinosaurus at 64 tonnes. I agree that Armstrong tends to under-flesh his skeletals, but since he does it universally we can still compare between his own estimates. Well, sort of, because his newer ones are nowhere near as under-fleshed as his Futalognkosaurus is, which to be fair seems to be from 2010. Shrink-wrapping was still really common even as recently as 2010.
I still think you are overestimating the size of the femur, because the 260 cm estimate is just based on a photograph with massive amounts of perspective distortion, whilst 240 cm was actually reported in the media, albeit not very widely. It would lower your 95 tonne estimate down to 75 tonnes... although I can't actually replicate that estimate myself. Hartman's Futalognkosaurus has a 184 cm femur, a 260 cm femur would thus imply a weight of 85 tonnes, while a 240 cm femur would imply 64 tonnes.
That said it might not matter much, because Scott Hartman's Alamosaurus only has a femur ~236 cm long when scaled to the size of the giant tibia. The low estimates I achieved for the giant Argentinian femur are thus more to do with basing it on Futalognkosaurus when really it seems like it would be every bit as large as the big Alamosaurus. Although Armstrong restores the Alamosaurus femur at over 3 meters long..
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Post by Deleted on Jun 5, 2015 10:11:15 GMT 5
^That compares to Armstrong estimating the largest Alamosaurus at 74 tonnes, and Argentinosaurus at 64 tonnes. I agree that Armstrong tends to under-flesh his skeletals, but since he does it universally we can still compare between his own estimates. Well, sort of, because his newer ones are nowhere near as under-fleshed as his Futalognkosaurus is, which to be fair seems to be from 2010. Shrink-wrapping was still really common even as recently as 2010. I still think you are overestimating the size of the femur, because the 260 cm estimate is just based on a photograph with massive amounts of perspective distortion, whilst 240 cm was actually reported in the media, albeit not very widely. It would lower your 95 tonne estimate down to 75 tonnes... although I can't actually replicate that estimate myself. Hartman's Futalognkosaurus has a 184 cm femur, a 260 cm femur would thus imply a weight of 85 tonnes, while a 240 cm femur would imply 64 tonnes. That said it might not matter much, because Scott Hartman's Alamosaurus only has a femur ~236 cm long when scaled to the size of the giant tibia. The low estimates I achieved for the giant Argentinian femur are thus more to do with basing it on Futalognkosaurus when really it seems like it would be every bit as large as the big Alamosaurus. Although Armstrong restores the Alamosaurus femur at over 3 meters long.. I have a tendency to put more credibility in SV-POW's estimate over media estimates. I really don't find the media a good source when other sources such as the SV-POW folks are available. You know the media... So I'll be sticking with the ~2.6-meter estimate until the paper comes out (hopefully open access) and states otherwise. I hope you understand why I distrust media estimates. I got ~95.2 tonnes via scaling based on the axial lengths. Scaling using the femurs, and again assuming a ~30-tonne Futalognkosaurus, I get ~84.6 tonnes. |
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blaze
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Post by blaze on Jun 5, 2015 10:51:46 GMT 5
Why are you taking their estimate based on assuming Pablo Puerta is 5'8'' tall rather than their 2.5m pallet estimate?
And Matt Wedel rises an interesting point in the comments.
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Post by Deleted on Jun 5, 2015 14:06:49 GMT 5
Why are you taking their estimate based on assuming Pablo Perta is 5'8'' tall rather than their 2.5m pallet estimate? I kinda overlooked that pallet estimate  But the pallet estimates are quite close, ~2.6 meters based on pallet A(about the same length) and ~2.5 meters based on pallet B. Taking the pallet B estimate lowers axial length to ~30.42 meters and that ~95.21 tonne axial-length-based estimate goes down to ~84.64 tonnes. The femur-based estimate ends up at ~75.25 tonnes. |
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Post by creature386 on Jun 5, 2015 20:42:09 GMT 5
I don't remember where, but didn't Ursus arctos (or someone else) say on carnivora that femur diameter and circumference tell more about the mass of an animal than the length (in cases they are used at all) because after all it matters how much weight they can carry. In case that's true, it is still not impossible that it (slightly) exceeded Argentinosaurus in size. |
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Post by theropod on Jun 5, 2015 22:22:42 GMT 5
Well, of course that is true in theory, tough at least in the past I recall a study that actually found a better correlation between body mass and femur length than between mass and circumference or some other measure of thickness. I’m not sure anymore what the name of the paper or its method was though I suppose there have been some recent improvements (only applying to bipeds of course, as quadrupeds were always less of a problem). Still, I’ll see whether I can find it again to see what I’m actually talking about. There will never be a perfect universal regression equation to estimate the mass from, thus I’m also always sceptical of estimates that base on attempts in that direction, but among related taxa, in the absence of better data I think femur circumference should be at least as viable as femur length. EDIT: This one→ found femur length to have a better correlation with body mass than circumference or width. It only applied to theropods, and I don’t know how sound the underlying assumptions are though. Still I wouldn’t dismiss the relevance of femur length. From a purely mechanical point of view, of course the thickness is what’s principally related to weight-bearing. However that’s not the only factor correlated with body mass, and linear dimensions can be important as well, as safety factors of the thickness often vary (as well as, probably, the internal built of the bone, which is also important for its strength) depending on individual lifestyles and levels of activity. Apparently in some cases (e.g. Acrocanthosaurus vs Tyrannosaurus) the discrepancy between animals with similar femur lengths and body masses can be quite extreme. |
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Post by Deleted on Jun 7, 2015 19:01:50 GMT 5
Size comparison between Tylosaurus and Giganotosaurus, both being the largest known specimens:  Seems that the "Bunker Mosasaur" T. proriger is roughly equal in size to the G. carolinii specimen MUCPv-95, although the Tylosaurus likely has an edge in mass due to a higher density. Based on Scott Hartman's estimates, MUCPv-95 is around ~8987 liters in volume. The mosasaur would have had a mass somewhere around ~8.99 tonnes if it was as dense as pure water, ~9.23 tonnes if it was as dense as the average density of seawater( SG of ~1.027), or ~9.55 tonnes if it was as dense as a human body( average SG of ~1.063). Giganotosaurus reconstruction from Scott Hartman, the Tylosaurus is taken from one of blaze's size charts. |
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Post by theropod on Jun 9, 2015 2:37:38 GMT 5
That reminds me, blaze, if you have time, would you mind doing another comparison similar to this one→ but using average size figures for C. megalodon and adding coherentsheaf’s Physeter-based estimate for Livyatan? So perhaps sharks at 13 and 14m TL, and if you want 15.1m to approximate mature females, compared to 13.5, 14.2 and 17.5m Livyatan (See edit). theworldofanimals.proboards.com/post/22843/threadtheworldofanimals.proboards.com/post/22781EDIT: Actually, it might be better to just use the Livyatan estimates not already used, in keeping with those for Megalodon. Speaking of the adjusted Physeter regression (14.2m) and the lower estimate based on Zygophyseter (16.2m). But I’ll let you decide. I think it would be best if you’d do it because everybody will be able to accept it as trustworthy. |
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Post by Grey on Jun 9, 2015 4:56:50 GMT 5
Would be very interesting though I'd recall the specimen of Livyatan, while an adult, was likely a full grown individual which achieved its life, on the other hand megs teeth suggesting 13-14m individuals are (for most) shed individually and thus do not firmly represent sharks that died at this point. This is further complicated by the hinted different sizes in geographical populations.
Nonetheless, that would certainly be a valuable chart.
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Post by theropod on Jun 9, 2015 11:38:49 GMT 5
I think we agreed that there wasn't actually any evidence for that, at least the last time I asked.
Geographical variations are to be expected, but that just means some populations will tend to be larger, others smaller than the overall average (and some will probbably bbe very close to it). The same can be said for sexual dimorphism, also inferrable for both of them.
Whether the animal died at this point or lost a tooth is not strictly relevant, animals don't die of old age, and they lose teeth throughout their whole life.
I'm not interested in only using sizes of senescent individuals, those I do not know for either of them and neither does anyone else according to my knowledge.
The previous comparison included only maximum size estimates for meg, so this one will definitely be an interestinng contrast.
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Post by Grey on Jun 9, 2015 11:53:54 GMT 5
I certainly agree about that, I just wanted to point on the potential differences between a taxon known by an individual which likely achieved its life (although I'd love to know the how old was Livyatan when it died, they'd just need to cut open some teeth) and animals that were most likely still growing when they shed their teeth. I'm certainly not arguing these sharks were all becoming 17-18 m behemoths but this point plus the differences in populations are to be expected and we can certainly guess it has been the case in Livyatan as well.
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