Largest sauropods

[theropod]

Even taking into account neck allometry, this is huge. Taylor and Wedel (2013) cited Parrish (2006) for the neck growing with an exponent of 1.35, so with a neck twice the size, the rest of the body would still be 1.67 times the linear size and 4.7 times as massive. With the mass of the neck being doubled and the AMNH vanilla Barosaurus being at least 10t in mass, we're probably looking at something around 50t here.

Funny, giant Diplodocus' size may get revised downwards, but other Diplodocids are being massively revised upwards.

[creature386]

Meet Austroposeidon, a new 25 m long titanosaurian from the Late Cretaceous of Brazil:
journals.plos.org/plosone/article?id=10.1371/journal.pone.0163373

[theropod]

Salisbury, S. W., Romilio, A., Herne, M. C., Tucker, R. T. and Nair, J. P. 2016. The Dinosaurian Ichnofauna of the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Walmadany Area (James Price Point), Dampier Peninsula, Western Australia. Journal of Vertebrate Paleontology 36 (sup1): 1–152.
Link→

The biggest complete sauropod pes print from the Broome sandstone (UQL-DP8-1) is described as 170-175cm long and 125 or 130cm wide, and there is a partial specimen (UQL-DP9-11) 140cm wide with a lower-bound estimate of 165-175cm that might have reached 200cm when complete, depending on measurement. So the early rumours of 2m tracks from Broome were either really lucky guesses, or they actually had some basis in the fossil record that just took a long while to be described in a credible source.

[spartan]

www.livescience.com/60080-largest-titanosaur-dinosaur-on-record.html

rspb.royalsocietypublishing.org/content/284/1860/20171219

No idea why they are saying 69 short tons and 62 metric tons in the article. In the paper they are speaking of 69 metric tons (range of 52-86) as far as I can see.

Applying the scaling equation for Patagotitan yields an estimated body mass of 69 tonnes ( + 17 tonnes standard error [37]), which is 10 000 kg (over 15%) more than the mass estimate obtained with the same equation for the largest titanosaur in which femur and humerus have been preserved ( Dreadnoughtus [12]) and twice the estimated body mass of several large Jurassic sauropods using the same equation (e.g. Giraffatitan , Apatosaurus [8]).

Body mass estimates for giant titanosaurs such as Argentinosaurus [13] and Puertasaurus [14] cannot be calculated using scaling equations due to the absence of limb elements; nonetheless, anterior dorsal vertebrae have been preserved in all of them(aswell asin Notocolossus ) and can therefore be directly compared. Comparing the area of these vertebrae (a two- dimensional equivalent to the volumetric method [38]) yields values that are approximately 10% smaller for these other taxa in comparison with Patagotitan (see electronic supplementary material, figure S3). The above-mentioned body mass estimates, as well as these vertebral comparisons, place Patagotitan as the largest known dinosaur species ( especially considering those for which a reliable mass estimation can be made).

Edit: svpow.com/2017/08/09/dont-believe-the-hype-patagotitan-was-not-bigger-than-argentinosaurus/#comments

[dinosauria101]

There is the OMNH 1331 Apatosaurus, which would've been 95 tons or more.

Also, as others said, Mamenchisaurus sinocanadorum. I find it to be somewhat overlooked due to the smaller species being better known

[theropod]

Mamenchisaurus sinocanadorum is generally "overlooked" because there’s so little solid information on its size, the alledged giant size mostly bases on Greg Paul’s claims about it, but would need more research in order to be worth much.

[dinosauria101]

Well there isn't much solid info on most giant sauropods, and I find Greg Paul's estimates to be fairly accurate overall, so 75 tons is pretty believable. Maybe I should have specified that it probably isn't well known because it's known from a few pieces of bone and there are 6 other species, all much better known

By the way, do you know how hilariously ironic it was to see 'Largest sauropods, by theropod' as the most recent post?

[theropod]

Like, not at all?

Well, it’s noteworthy that the original description of M. sinocanadorum estimates the holotype at just 26m, and fairly lightly built (presumed comparable in mass to Diplodocus. Many (but not all) supposedly giant animals are hoaxes that turn out to not be as big as claimed upon closer examination. That is not to say the existence of a genuine giant is necessarily implausible, but it’s generally a good idea to at least have a grasp on actual, measurable sizes of real remains, rather than vague claims about overall sizes of fragmentary specimens from a single source.
That being said, I have not done much reading up on M. sinocanadorum, I don’t know if Paul is talking about the holotype specimen, of what size the specimens he’s talking about are (note that even if he’s correct in that the species reached 35m, his mass estimates still seem oddly high for an animal mostly consisting of neck.
All I’m saying is that I’d like more info than I have seen before, so that there’s actually stuff for discussion and not just a listing of entries of "source A said sauropod X was wee big without providing an explanation. Period.".
Perhaps you have, and can share some measurements, which would fall under what this thread is for?

[dinosauria101]

^Did not know that. Just came here to give my 2 cents on what I know about giant sauropods

[dinosauria101]

Nov 16, 2019 19:07:18 GMT 5 theropod said:

Also, on an unrelated note, 75 t seems highly doubtful for this reconstruction. I made a fairly generous blender model for Paul’s skeletal scaled to 35 m axial length, and got around 58 m³ for the entire axial segment. I’m too lazy to model the legs right now, but if the thing wants to have a shot at reaching 75 t, they would have to add around 30 t, which seems clearly impossible.
EDIT: ok, I got over my lazyness. As expected, nope. The hindlegs segments are a little over 600kg each and the forelimbs slightly shy of that, giving us a total volume of around 60 m³. At a density of 0.8, this gives us around 48 t, not 75.

Alright, so I missed this and would like to address it.

From what I can tell, 75 tonnes seems to indeed hold water. That is what Spinoinwonderland's GDI got: www.deviantart.com/spinoinwonderland/journal/Some-more-GDI-s-for-a-few-folks-659947404
Here is the specific skeletal and dimensions:

(yes, it does give 73.64 tonnes, but that's very close to 75, and 75 tonnes is also within the margin of error, ~20% IIRC)
Besides, 48 tonnes seems very lean for this skeletal - scaling a Mamenchisaurus hochuanensis to 76 tonnes gets it at about 38 meters, and M. hochuanensis is more neck, more tail (I think?) and more gracile than M. sinocanadorum. Maybe it's just me, but 48 tonnes looks quite conservative.

[theropod]

I do intend to recheck my scaling on that and make a proper post on "animal sizes" then. But do note that at a realistic density of 0.8, that volume figure by broly actually gives 69 t.

[dinosauria101]

I used the recommended density of 0.85, which also gives 51 tonnes for your 60 cubic meter skeletal.

[dinosauria101]

Just some food for thought on Xinjiangtitan:
Scaling down from M. sinocanadorum gives ~47.23 tonnes at 30 meters, ~52.11 tonnes at 31 meters, and ~57.32 tonnes at 32 meters. Pretty good size!

[Infinity Blade]

So, the giant Oklahoma Apatosaurus specimen is apparently a possible contender for one of the largest sauropods->. Anything else that approaches or even exceeds this weight?

[dinosauria101]

BYU 9024 Barosaurus, and the French Monster