Largest sauropods

[coherentsheaf]

Re: Parabrontotpodus

Scaling from Scott Hartman's Supersaurus restauration gives me 41.6m. At this length the animal should weigh about 70 tonnes.

[Fragillimus335]

I get ~45m measuring along the midline of the track. Supersaurus has a somewhat shorter tail than Dippy, so lengths of 45-55 are possible. Using Hartman's diplodocus I get ~53 meters. Still an awfully big beast, probably in the 70-110 metric ton range. Still in the range of mortal sauropods! The only two real freaks so far are Broomy and Amphicoelias.

[theropod]

But the link you posted was the Broome track, not Parabrontopodus. Why is Parabrontopodus deformed iyo, and Broome isn't?
What about Plagne, couldn't 1,5m just as easily be width? That is said on SVPOW at least.

[Fragillimus335]

May 22, 2013 16:31:51 GMT 5 theropod said:

But the link you posted was the Broome track, not Parabrontopodus. Why is Parabrontopodus deformed iyo, and Broome isn't?
What about Plagne, couldn't 1,5m just as easily be width? That is said on SVPOW at least.

Whoops! I forgot to include the link! ars.els-cdn.com/content/image/1-s2.0-S0016699509000904-gr4.jpg

To sum it up, the Parabrontopodus tracks are shaped like bananas. They are surely slip marks. The Broome tracks have the proportions of normal titanosaur tracks. The reason I doubt the plagne tracks are 1.5 wide is the images, the people standing around the prints are much larger, the prints look a little over 1 meter wide.

[theropod]

Oh yeah, I see. Those are definitely deformed.

The image doesn't necessarily show the largest tracks. If you take some random image from thulborn's publication, it very likely won't show the record-nreakers either.

[Fragillimus335]

May 23, 2013 1:44:22 GMT 5 theropod said:

Oh yeah, I see. Those are definitely deformed.

The image doesn't necessarily show the largest tracks. If you take some random image from thulborn's publication, it very likely won't show the record-nreakers either.

That's true, but in general when a measurement is quoted, it is length, not width. Especially a sensationalistic news report, they would claim the largest dimension, which would be length. Although I did hope they were 1.5m wide, it probably isn't the case. The Broome tracks on the other hand may be close to that size. There is even talk floating around of some tracks 2 meters wide, but even the sauropod lover in me doubts those! It seems the contenders for biggest sauropod of all time are Amphicoelias and the Broome titanosaur. My current best GUESSES for their dimensions are:

Amphicoelias, based on Barosaurs and diplodocus.

Length:~82 meters
weight:~320 metric tons
Back height:~12.5 meters

Broome titanosaur, based on Brachiosaurus and Alamosaurus.

Length:~51 meters
Weight:~240 metric tons
Shoulder height:~11.8 meters


All guesstimates of course! And even though these estimates may seem high, remember that almost all large animals have freak specimens ~80% heavier than the median weight of the species.

[creature386]

IMO, this belongs in a Sauropod overview therad:
www.ncbi.nlm.nih.gov/pmc/articles/pmc3045712/
They don't seem to be opponents of 100 t+ Sauropods, but they also point out that there are no methods given for the 100 t+ mass numbers. It looks like they don't accept simple scaling as a method, they wrote "no methods" when talking about Wedel's estimate for Sauroposeidon, where he simply scaled up from Giraffatitan.

[Fragillimus335]

May 24, 2013 1:02:45 GMT 5 creature386 said:

IMO, this belongs in a Sauropod overview therad:
www.ncbi.nlm.nih.gov/pmc/articles/pmc3045712/
They don't seem to be opponents of 100 t+ Sauropods, but they also point out that there are no methods given for the 100 t+ mass numbers. It looks like they don't accept simple scaling as a method, they wrote "no methods" when talking about Wedel's estimate for Sauroposeidon, where he simply scaled up from Giraffatitan.

Yep, that is a fantastic paper that I have cited many times! I am 100% sure there were sauropods that massed over 100t, and pretty sure there were a few that may have exceeded 200t. What I wouldn't give to see one alive today!

[Grey]

I follow and I agree with the thoughts of Zack Armstrong and Mike Taylor on SVPOW : anything in 90-150 tons for A. fragillimus has the same level of credential. I've seen none suggesting a 200 tons mark. Like Mike Weddel justifiably remarked, favoring 200 tons is counting the hits and ignoring the misses.

We should learn to relativise this kind of thoughts and predictions.

So no, I strongly disagree with the enthusiastics claims of 200 tons for this sauropod. This is pretty much like if I was coming all the time with claims of 114 short tons figures for C. megalodon (which still remain published and used figures in litterature), all of this with enthusiastics smileys.

My main goal is that we keep mature and cautious manners in our discussions.

[creature386]

Grey, what do you think of 100 t+ Sauropods? Because that seemingly is the main discussion in that therad.

[Grey]

I think this is quite reasonnable for some of the very biggest ones, I have no problem with that. Only I recall that weight estimates in sauropods all the time fluctuate, see with Argentinosaurus. 100 tons + is a reasonnable top mark but I wouldn't be surprised if the contenders end up with weights closer to 80 tons. Of course then we can count that the all-time biggest individuals might have reached the 100 tons marks or not, but that's a matter of big speculation.

[theropod]

Under the premise that The neural arch of A. fragillimus was the reported size, it indicates a vertebra 2,3-2,7m tall (Taylor/Carpenter) in dorsoventral depth. I somehow prefer the scaling from Carpenter, buit that is probably subjective.
However I noticed variance in the proportions of the vertebrae both said to be "cope's figure of an A. altus vertebra" here:
svpow.com/2010/02/19/how-big-was-amphicoelias-fragillimus-i-mean-really/

Using Carpenter's metod of scaling up D. carnegii, that would make it 70m long and 200t (very conservative 10,25t Diplodocus), being 2,7 times the dimensions. This is exactly the same as Carpenter did, just using a corrected figure for Dippy's vert. It may not be accurate considering other scaling-analogies, but it has enough credential to be called an estimate.

Stomatopod had some comparisons with other, perhaps phylogenetically closer taxa, that yielded far lower lenghts, and probably also significantly lower weights, he might want to repost them.

[Grey]

Like I said, I consider it an estimate, but not a reasonnable one for the reasons mentionned earlier.

I would quote again Matt Wedel about that.

Turning to A. fragillimus, the piece of vertebra that was preserved does not really tightly constrain the total size of the vertebra, and estimates of the vertebraÂ’s total height vary by something like 25%. CarpenterÂ’s (2006) estimates are all based on the upper end of the range. Also, the vert was extremely lightly built, much lighter than comparable vertebrae from Diplodocus. We know that vertebral pneumatization knocked down the volumetric mass of Diplodocus, and it does not seem unreasonable that A. fragillimus might have been lighter than a scaled-up Diplodocus would have been.

The third caveat is that the estimates of 120-160 metric tons for B. and A. are already based on long chains of ‘ifs’. To take those estimates as data, assume that they represent average individuals of their respective species, and then jump onward to imagine world-record individuals massing more than 200 tons is to pile uncertainty on top of uncertainty and speculation on top of speculation, while ignoring all the if/then decision points that led to the original estimates. People are welcome to do that, but no one is compelled to take it seriously.

The bottom line is that the evidence for whales weighing 190-200 metric tons is pretty darn good, and the evidence for sauropods weighing even 150 tons is frankly pathetic. So until much better evidence for the gigapods emerges, I’ll continue to award the “Heaviest Vertebrate Ever” prize to the blue whale.

[Supercommunist]

How would a sauropod even reach weights of 200 tons or more to begin with? At the eighty ton mark they are already immune to predation, any larger and their size becomes detrimental to their survival.

[Grey]

That's true as well. The ecological and physiological issues and differences between a 50 tons animal and a 150 tons one are obvious.