gigadino96
Junior Member
Vi ravviso, o luoghi ameni
Posts: 226 
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Post by gigadino96 on May 26, 2013 3:05:48 GMT 5
The blue whale looks so small compared to Amphicoelias. I do not understand why there are still many sources that say that the blue whale is the largest animal every lived.
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Fragillimus335
Member
Sauropod fanatic, and dinosaur specialist
Posts: 573
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Post by Fragillimus335 on May 26, 2013 3:30:08 GMT 5
The blue whale looks so small compared to Amphicoelias. I do not understand why there are still many sources that say that the blue whale is the largest animal every lived. Well most people still believe Amphicoelias only weighed ~125 tons. When it likely weighed well over 200t. Big Blue was probably 2nd or 3rd in the lineup of biggest animal ever. |
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Post by Grey on May 26, 2013 6:13:14 GMT 5
Absolutely not convinced by this 200 tons Amphi. Nothing published, nothing seriously spotted. I watch very regularly SVPOW which is certainly the world reference when it comes to sauropods, and even if it is possible, there is absolutely no conclusive evidences or even indications that Amphi reached that large. All these numbers and scales and so are over-optimistic extrapolations based on over-optimistic speculations.
Sorry but basically, ask to any serious specialist in megafauna, paleo or extinct, he will argue that the blue whale still owns the record. And I doubt any land animal ever approached the largest specimens.
I'm not interested in these lengthy discussions about numbers and interpretations, all of this on a bone we've lost 120 years ago. I did the same thing when I was calculating the size of the Monster of Aramberri and came up with a 25-30 m pliosaur. We all know the following...
And really, no offense but I'd like to avoid this kind of fantasies like this on the board guys, this is not carnivora or topix.
We all love giants here, in my case giants predators, but when years ago I was enthusiast with hypothetical 25 m sea top carnivores, today I'm very happy with 12 or 15 m big badass beasts. These suggestions of sauropods weighing several hundred of tons on carnivora were frankly and really ridiculous...and boring.
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Fragillimus335
Member
Sauropod fanatic, and dinosaur specialist
Posts: 573
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Post by Fragillimus335 on May 26, 2013 7:09:57 GMT 5
Absolutely not convinced by this 200 tons Amphi. Nothing published, nothing seriously spotted. I watch very regularly SVPOW which is certainly the world reference when it comes to sauropods, and even if it is possible, there is absolutely no conclusive evidences or even indications that Amphi reached that large. All these numbers and scales and so are over-optimistic extrapolations based on over-optimistic speculations. Sorry but basically, ask to any serious specialist in megafauna, paleo or extinct, he will argue that the blue whale still owns the record. And I doubt any land animal ever approached the largest specimens. I'm not interested in these lengthy discussions about numbers and interpretations, all of this on a bone we've lost 120 years ago. I did the same thing when I was calculating the size of the Monster of Aramberri and came up with a 25-30 m pliosaur. We all know the following... And really, no offense but I'd like to avoid this kind of fantasies like this on the board guys, this is not carnivora or topix. We all love giants here, in my case giants predators, but when years ago I was enthusiast with hypothetical 25 m sea top carnivores, today I'm very happy with 12 or 15 m big badass beasts. These suggestions of sauropods weighing several hundred of tons on carnivora were frankly and really ridiculous...and boring. Try estimating it yourself. The numbers give you 200 ton+ sauropods given basic diplodocid body plans. High numbers do not mean inaccurate numbers. If we accept in Carpenter's 2.7 meter vert and 4.6 meter femur, this is a likely size for Amphicoelias. Just because something isn't published doesn't mean it is impossible. And by the way, the size of Amphicoelias HAS been published, literally just fix Carpenter's scaling mistake, and you get these numbers. You may not think sauropods are interesting, but I think such massive animals are fascinating. I think how these creatures survived biologically is one of paleontology's greatest mysteries! |
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Post by Grey on May 26, 2013 7:26:49 GMT 5
I've read this and I've read too counter argumentation by educated AND rationnal guys like coherentsheaf, stomatopod... Such a gross mistake has so far not been hinted on SVPOW or anywhere else and sorry but I would consider them as a serious source.
I don't think sauropods are uninteresting, I think such discussions giving such extreme figures are boring and typically the kind we can find on forums.
I mess with concrete datas and the one I've found do not support ideas of such animals. Not a matter of biased or not calculations but of rationnal viewpoint.
And I don't even talk about the others massive issues for such organisms, as much by ecological and physiological viewpoints. That's already a very problematic question for well known giants like Brachiosaurus, Giraffatitan...
Also, at the end of the day, all giants are downsized with time and knowledge, even if they remain true giants. As we have no mean to explore further the biology and ecology of this species, this kind of discussion is a definitive dead end at now and thus, not needing to be discussed that long. I'm done with spending times on over-enthusiastic predictions of lost specimens that nobody has seen alive...
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Fragillimus335
Member
Sauropod fanatic, and dinosaur specialist
Posts: 573
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Post by Fragillimus335 on May 26, 2013 8:35:17 GMT 5
Eh, then leave the discussing to the rest of us. And others have noticed these problems.
Zach Armstrong:
Amphicoelias fragillimus...bigger than you think!
by ~palaeozoologist, Jan 21, 2011, 4:04:30 PM
Journals / Personal
So I'm interested in sauropod size, and I was wondering how Ken Carpenter got his mass and length estimate in his paper on Amphicoelias fragillimus since I'm kinda a numbers guy. This is what I found, if you're interested, and I posted this stuff on the DML (Dinosaur Mailing List) a week or so ago (slightly edited):
Carpenter (2006) in his review of Amphicoelias fragillimus reconstructed a height of 2.7 meters for the posterior dorsal based off comparisons to A. altus. Now he estimated a length of 58 meters and a mass of 122,400 kg. This is his method for these calculations: "Assuming that the mega-diplodocids are scaled up versions of Diplodocus, then the volume (hence mass) changes in proportion to the third power of the linear dimension (Schmidt-Nielsen, 1984). Thus, if Diplodocus carnegii had a length of 26.25 m and mass of 11,500 kg (Paul, 1994), then A. fragillimus had a mass of around 122,400 kg, which is still within the hypothesized maximum mass for a terrestrial animal (Hokkanen, 1986)." Now, the mass follows if we assume that *A. fragillimus* was 58 meters, and D. carnegii was 26.25 meters. This means A. fragillimus was 58/26.25=2.2 times as big in linear dimensions. This means it should be (2.2)^3=10.648 times as voluminous and thus presumably that many times more heavier than D. carnegii. So 11,500*10.648=122,452 kg. So that makes sense.
However, where did Carpenter get the length estimate for A. fragillimus? He based it off of D. carnegii, as mentioned above and cited the stats for the latter from Paul (1994). However, Paul (1994) did not list a mass of 11,500 kg and a length of 26.25 meters for D. carnegii. He listed a mass of 11 tonnes and a length of 24.8 meters. So where did the mass estimates that Carpenter cited come from? I don't know. Am I missing something here? Maybe someone else can help me out here.
But that's not all. If A. fragillimus is supposed to be 2.2 times larger in linear dimensions, then going backwards from the estimated height of 2.7 meters estimated for the lone preserved dorsal in A. fragillimus means that the dorsal vertebrae of D. carnegii should 2.7/2.2=1.22 meters tall. Now, my digital copy of Hatcher's (1901) description of the CMNH 84 specimen of D. carnegii lists the 9th dorsal as 94.6 cm tall and the 10th dorsal as 96.6 cm tall (even the supposed "11th dorsal" was only 105.1 cm tall). So, somehow Carpenter thought that the comparable dorsal in D. carngeii was somewhere between 25.4 and 27.4 cm taller than it actually was. In fact, Lucas et al.'s (2006) taxonomic revision lists the 9th dorsal as about 1.2 meters tall for the "seismosaur" specimen. So Carpenter in essence assumed that an individual Diplodocus with seismosaur-sized vertebrae only massed about 11.5 tonnes and was 26.25 m long, even though more recent estimates of the seismosaur's size are around 30 tonnes in mass and 30-32 meters in length.
So what happens if we scale off the actual measurements listed for the CMNH 84 D. carnegii specimen? Well, assuming the dorsal in A. fragillimus was the 10th dorsal, then it was 2.7/0.966=2.79 times larger in linear dimensions than that *Diplodocus* specimen. If that specimen was indeed 24.8 meters as Paul (1994) says, than an estimated length for A. fragillimus is around 69 meters, a full 11 meters longer than Carpenter originally estimated. The disparity is even worse if we assume a 26.25 m Diplodocus individual which gives us an estimated length of around 73 meters.
What about mass? Well, if A. fragillimus was 2.79 times larger in linear dimensions than D. carnegii, then it was (2.79)^3=21.7 times more voluminous and therefore more massive. So, assuming that the CMNH 84 specimen was indeed 11.5 tonnes, then A. fragillimus should be 21.7*11.5=249.55 tonnes (!). This is almost 130 tonnes heavier than estimated by Carpenter, and is larger than the largest Blue Whale specimens that I have heard about, the largest of which may have been at least 200 tonnes in mass based off oil yield. Even using Greg Paul's more precise estimate of 11.4 tonnes listed on his website for the CMNH 84 Diplodocus still gives a mass of over 247 tonnes. I find this mass estimate of nearly 250 tonnes difficult to swallow. Paul uses a density of 0.9 for the body excluding the neck, even if we assume that this should be about 0.8 as indicated by work done on pneumaticity in sauropods done by Matt Wedel, this would mean we could reduce the mass to be about 88% of of the original mass which reduces it only to 219 tonnes, which is still fairly unbelievable. So, here's the big question: is there some major flaw in my reasoning here?
For the record, I think Carpenter's estimated height for A. fragillimus is reasonable. I did a similar scaling technique using GIMP's measuring tools and got an estimated height of 2.65 meters for the vertebrae based off of A. altus. Using this slightly reduced measurement, you still get a mass estimate of around 235-237 tonnnes (depending on how many decimal places you want to truncate) which is still around 110 tonnes heavier than estimated by Carpenter and is still heavier the heaviest known Blue Whales.
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Post by Grey on May 26, 2013 17:32:54 GMT 5
Enthusiastics propositions on the net. Like I said, I did the same with pliosaurs at one time, trying to demonstrate they were bigger than thought by paleobiologists.
I've read and I know what think Matt Wedel and others of this kind of commentary, I ll don't engage a debate for this.
Note : I don't argue of the absolutely impossibility of all of this, but I believe and use actual and more verifiable datas.
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Post by theropod on May 26, 2013 18:15:24 GMT 5
If arguing Blue Whale-sized sauropods are not feasible, this is valid, but don't do so just because they are not published!
Coherentsheaf and Stomatopod have brought up valid points based on phylogeny and scepticism based on the fossil being lost. Both are logical, as long as in agreement with the estimates used for other animals (you can hardly ignore any estimate for Amphicoelias and at the same time go on inventing a 14-16m T. rex specimen or stuff like that).
Something being published however doesn't mean it is reliable (30m triassic kraken) and something not being published doesn't make it non-existant (most estimates for C. megalodon-and yes, this is basically the same. Carpenter envisioned Amphicoelias as an upscaled Diplodocus carnegii, he merely got the vertebral height wrong. Filling in the proper vert-height is just like using some teeth you can find for deriving an estimate)
If Diplodocus carnegii is 26m and 10,25t (as per Wedel's estimate with adjusted density), an Amphicoelias is 2,7 times the dimensions, that would make it 70m and 200t. That doesn't mean this is the best estimate, it doesn't even have to be a good estimate, but it cannot just be whiped aside, especially if you require authorities agreeing as this bases on Carpenter's metod. It is a real figure, not something made up by some fanboy. It might be only half that weight, no-one knows.
Does anyone have a copy of Hatchers Dippy-paper? fragillimus might have access...
Sadly, the login-data for JSTOR creature originally posted on carnivora don't seem to work anymore.
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Post by Grey on May 26, 2013 18:23:42 GMT 5
That's exactly what I argue, I don't spit on that, everything is possible, but the skepticism is massive here. Not a matter of publication, I've read what think about that the guys of SVPOW, no one takes seriously these propositions even if they remain open-minded. But fragillimus uses this as a fact in his comparisons scales.
When I use (or more likely ask to fellow members to do comparisons^^), I use reasonnable and at best not upper estimates, for cautiousness. A 70 m Amphicoelias is not reasonnable.
Note : most estimates/methods for C. megalodon are published, only in this particular case, they do not represent the maximum size each time, except for the suggestions by Gottfried in 1996. So we can use published methods for each tooth allowing an estimate.
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Post by creature386 on May 26, 2013 18:50:54 GMT 5
Sadly, the login-data for JSTOR creature originally posted on carnivora don't seem to work anymore. I thought my computer was simply stupid, when I couldn't log in. I can understand you. |
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Post by theropod on May 26, 2013 18:58:29 GMT 5
Yes, we can also use published measurements of Diplodocus vertebrae, can't we? That would yield 70m, with a published metod. That may be liberal, but many metods are.
Comparisons reflect opinions and estimates, not facts. What is perceived as reasonable is merely opinion. To show an upper estimate that is more or less optimistic is valid. Of course showing a lower estimate as well would be better...
Just as with megalodon, there's lot of speculation in the estimates, which therefore fluctuate. In neither case that means we could just ignore the upper end.
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Post by theropod on May 26, 2013 18:59:10 GMT 5
Sadly, the login-data for JSTOR creature originally posted on carnivora don't seem to work anymore. I thought my computer was simply stupid, when I couldn't log in. I can understand you. that's so frustrating, isn't it? What for did they publish those access details on the web if they don't work? |
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Post by Grey on May 26, 2013 19:03:24 GMT 5
Personnally I ignore it most of the time, much like are doing the SVPOW guys...
This kind of discussion on the internet looks more like a race to the first which will beat the blue whale. No, I don't take this too seriously. And really I don't want to see the board full of this kind of suggestions or we could lose our credential.
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Post by theropod on May 26, 2013 19:29:47 GMT 5
It might be better to move this discussion to the thread I made for giant sauropods. But that race idea is just the same as with "king of the dinosaurs", "largest theropod", or "largest predator of all time". The only difference is that in those cases there is no tradition of an unbeat extant champion.
If you can do the exact same thing that yields a 200t amphicoelias with megalodon and agree with the upper end, I don't see why you shouldn't at least accept others supporting aforementioned sauropod as a reasonable popssibility. The analogy is not perfect, but it is a very similar case, with the notable difference it is not a vertebrae but a tooth, and there are obviously experts eager to find the mother of all predators.
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Post by Grey on May 26, 2013 19:42:02 GMT 5
There was a "largest theropod", there was a "largest top predator ever", but there was no "king of the dinosaurs" in technical terms and there is no serious scientific racing to found an sauropod beating the blue whale. That's just a goal you found on many discussions on the net by, often young, enthusiasts.
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