The biggest dinosaurs that lived on Earth

[DinoFan83]

Antarctosaurus giganteus size

Here are some size figures I have obtained for Antarctosaurus giganteus.
All these are scaled to 235 cm femur catalogued as MLP 26-316, as per Mazzetta (2004), as well as an uncatalogued 250 cm femur in the Museo de La Plata mentioned in Paul (1994) that likely belongs to Antarctosaurus giganteus.
It is very incomplete and is only known from large femora (von Huene 1929 and Paul 1994), therefore its size and proportions are mostly conjecture. As such, to get a rough idea of its size, I will scale several other titanosaurs to lengths of 235 and 250 cm femur. For base sauropods, I am using lognkosaurs (such as Ruyangosaurus, Futalognkosaurus, Argentinosaurus, and Patagotitan) and derived lithostrotians (such as Saltasaurus, Diamantinasaurus, Paludititan, Opisthocoelicaudia, and Dreadnoughtus) because they have ended up close to Antarctosaurus in several phylogenetic analyses (such as Poropat 2014, Lacovara 2014, Gonzales Riga 2016, Carballido 2017, Gonzales Riga 2018, Mannion 2019, and Gonzales Riga 2019). I am also using other antarctosaurids such as Bonitasaura, Antarctosaurus wichmannianus, and Antarctosaurus brasiliensis because they, as antarctosaurids, are very closely related to Antarctosaurus giganteus and would almost certainly be similar to it.

Mass estimations and scaling:

Based on a 10 meter, 5 tonne, 105 cm femur Bonitasaura (Apesteguia 2004, Paul 2010, Paul 2016 and GetAwayTrike), I get ~30 meters and ~67.64 tonnes for the 235 cm femur, and ~31.91 meters and ~81.43 tonnes for the 250 cm femur, with the larger neck and tail that Antarctosaurus giganteus would have factored in (I used the proportions of this Opisthocoelicaudia GDI assuming a 1/2 as long and voluminous neck, to account for Bonitasaura proportions, and the proportions of this Patagotitan GDI to calculate the percentage of length/mass increase; when scaling the Bonitasaura up with no changes assumed whatsoever, I get ~22.38 meters and ~56 tonnes for the 235 cm femur, and ~23.8 meters and ~67.48 tonnes for the 250 cm femur).

Based on a 33.5-37 meter, 80-90 tonne, 250 cm femur Argentinosaurus (randomdinos, Paleo King, Benson 2014), I get ~31.49-34.78 meters and ~66.46-74.75 tonnes for the 235 cm femur, and about the same (as the Argentinosaurus) for the 250 cm femur.

Based on a 26 meter, 40+ tonne, 190 cm femur Futalognkosaurus (Calvo 2007, Calvo 2008, Benson 2014 and Paleo King, note that the real Futalognkosaurus is probably significantly larger than this but it would not change the proportions), I get ~32.15 meters and ~76+ tonnes for the 235 cm femur and ~34.2 meters and ~91.5+ tonnes for the 250 cm femur.

Based on an 18 meter, 15 tonne, 130 cm femur Antarctosaurus wichmannianus (Ornithopsis), I get ~32.53 meters and ~88 tonnes for the 235 cm femur, and ~34.6 meter and ~105.9 tonnes for the 250 cm femur.

Based on a 15 meter, 10 tonne, 115 cm femur Antarctosaurus brasiliensis (Arid and Vizotto 1971, randomdinos), I get ~30.65 meters and ~85.33 tonnes for the 235 cm femur, and ~32.6 meters and ~102.73 tonnes for the 250 cm femur.

Based on a 26 meter, 48.45 tonne, 190 cm femur Dreadnoughtus (Lacovara 2014, SVPOW and SpinoInWonderland, note that this is only one reconstruction and other estimates, such as Bates et al. 2015 will get differing results; I used the skeletal from Lacovara, which SVPOW GDI'd and got 57 cubic meters and thus 48.45 tonnes with the proper density of 0.85), I get ~32.15 meters and ~91.6 tonnes for the 235 cm femur, and ~34.2 meters and ~110.2 tonnes for the 250 cm femur.

Based on an 8 meter, 2.5 tonne, 81.6 cm femur Saltasaurus (Paul 2010, Paul 2016), I get ~31 meters and ~67.5 tonnes for the 235 cm femur, and ~32.97 meters and ~81.26 tonnes for the 250 cm femur, with the larger neck and tail that Antarctosaurus giganteus would have factored in (I used the proportions of this Saltasaurus GDI* and the proportions of this Patagotitan GDI to calculate the percent of mass and length increase; when scaling the Saltasaurus up with no changes whatsoever assumed, it would be ~23 meters and ~59.4 tonnes for the 235 cm femur, and ~24.5 meters and ~71.89 tonnes for the 250 cm femur).

Based on a 31 meter, 60 tonne, 207 cm femur Ruyangosaurus (Sassani and Bivens 2017, Paleo King), I get ~35.19 meters and ~87.8 tonnes for the 235 cm femur, and ~37.43 meters and ~105.7 tonnes for the 250 cm femur.

Based on a 30-33 meter, 53-69 tonne, 236 cm femur Patagotitan (Carballido 2017, randomdinos), I get approximately the same for the 235 cm femur, and ~31.91-35.1 meters and ~63.81-83 tonnes for the 250 cm femur.

Based on a 16 meter, 15 tonne, 135 cm femur Diamantinasaurus (Hocknull 2009, Poropat 2014), I get ~27.85 meters and ~79.12 tonnes for the 235 cm femur, and ~28.84 meters and ~95.25 tonnes for the 250 cm femur.

Based on an 8.73 meter, 1.92 tonne, 70 cm femur Paludititan (Megalotitan), I get ~29.3 meters and ~72.64 tonnes for the 235 cm femur, and ~31.17 meters and ~87.46 tonnes for the 250 cm femur .

Based on a 15 meter, 10.5 tonne, 130 cm femur Opisthocoelicaudia (Seebacher 2001 and Scott Hartman), I get ~27.11 meters and ~62 tonnes for the 235 cm femur, and ~28.85 meters and ~74.67 tonnes for the 250 cm femur.

Resulting masses and lengths:

The estimated masses range from ~53 tonnes to ~91.6 tonnes for the 235 cm femur, with a mean of ~75.76 tonnes, and from ~63.81 to ~110.2 tonnes for the 250 cm femur, with a mean of ~91.22 tonnes - these are very comparable to the masses that several publications have obtained, such as van Valen 1969 (80 tonnes), Mazzetta 2004 (69 tonnes), and Paul 1994 (80-100 tonnes).
The estimated lengths range from ~27.11 to ~35.19 meters for the 235 cm femur with a mean of ~31 meters, and from ~28.85 to ~37.43 meters for the 250 cm femur, with a mean of ~33 meters - both are fairly similar to what some of the aforementioned publications such as van Valen 1969 (30 meters) and Paul 1994 (30-35 meters) have obtained.

I personally think something roughly in the size range of ~30-35 meters and ~80-100 tonnes (most similar to Paul, 1994) is most likely for both specimens since it's from very close relatives (such as Antarctosaurus wichmannianus and Antarctosaurus brasiliensis), but any of these are on the table.

References:

Mazzetta, G.V.; Christiansen, P.; Fariña, R.A. (2004). "Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs"
G.S. Paul, 1994, "Big sauropods — really, really big sauropods", The Dinosaur Report, The Dinosaur Society
von Huene, F. 1929. Los saurisquios y ornitisquios del Cretacéo Argentino. Anales del Museo de La Plata (series 3) 3: 1–196.
Poropat, S.F.; Upchurch, P.; Mannion, P.D.; Hocknull, S.A.; Kear, B.P.; Sloan, T.; Sinapius, G.H.K.; Elliot, D.A. (2014). "Revision of the sauropod dinosaur Diamantinasaurus matildae Hocknull et al. 2009 from the mid-Cretaceous of Australia: Implications for Gondwanan titanosauriform dispersal"
Lacovara, Kenneth J.; Ibiricu, L. M.; Lamanna, M. C.; Poole, J. C.; Schroeter, E. R.; Ullmann, P. V.; Voegele, K. K.; Boles, Z. M.; Egerton, V. M.; Harris, J. D.; Martínez, R. D.; Novas, F. E. (September 4, 2014). "A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina"
González Riga, Bernardo J.; Lamanna, Matthew C.; Ortiz David, Leonardo D.; Calvo, Jorge O.; Coria, Juan P. (2016). "A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot"
Carballido, J.L.; Pol, D.; Otero, A.; Cerda, I.A.; Salgado, L.; Garrido, A.C.; Ramezani, J.; Cúneo, N.R.; Krause, J.M. (2017). "A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs"
Gonzalez Riga, B.J.; Mannion, P.D.; Poropat, S.F.; Ortiz David, L.; Coria, J.P. (2018). "Osteology of the Late Cretaceous Argentinean sauropod dinosaur Mendozasaurus neguyelap: implications for basal titanosaur relationships"
Mannion, P.D.; Upchurch, P.; Jin, X.; Zheng, W. (2019). "New information on the Cretaceous sauropod dinosaurs of Zhejiang Province, China: impact on Laurasian titanosauriform phylogeny and biogeography"
González Riga, Bernardo J.; Lamanna, Matthew C.; Otero, Alejandro; Ortiz David, Leonardo D.; Kellner, Alexander W. A.; Ibiricu, Lucio M. (2019). "An overview of the appendicular skeletal anatomy of South American titanosaurian sauropods, with definition of a newly recognized clade"
Apesteguía, S. 2004. Bonitasaura salgadoi gen. et sp. nov.: a beaked sauropod from the Late Cretaceous of Patagonia.
Paul, G.S. 2010. The Princeton field guide to dinosaurs. Princeton University Press, Princeton.
Paul, G.S. 2016. The Princeton field guide to dinosaurs. 2nd Ed.. Princeton University Press, Princeton.
www.deviantart.com/getawaytrike/art/La-Bonita-614216886
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Benson, R. B. J.; Campione, N. S. E.; Carrano, M. T.; Mannion, P. D.; Sullivan, C.; Upchurch, P.; Evans, D. C. (2014). "Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage"
Calvo, J.O., Porfiri, J.D., González-Riga, B.J., and Kellner, A.W. (2007) "A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur"
Calvo, J.O.; Juárez Valieri, R.D. & Porfiri, J.D. 2008. Re-sizing giants: estimation of body length of Futalognkosaurus dukei and implications for giant titanosaurian sauropods."
www.deviantart.com/paleo-king/art/Futalognkosaurus-dukei-Mk-IX-694212525
www.deviantart.com/paleo-king/art/Futalognkosaurus-dukei-Mk-X-Calvo-edition-696697321
www.deviantart.com/ornithopsis/art/Antarctosaurus-wichmannianus-716495860
www.museocivico.rovereto.tn.it/UploadDocs/3325_Arid_Vizotto_1971.pdf
www.deviantart.com/randomdinos/art/Sauropodomorphs-of-Brazil-692949806
svpow.com/
www.deviantart.com/spinoinwonderland/art/Dreadnoughtus-schrani-skeletal-reconstruction-515239568
Sassani N, Bivens G.T. (2017) The Chinese colossus: an evaluation of the phylogeny of Ruyangosaurus giganteus and its implications for titanosaur evolution
www.deviantart.com/paleo-king/art/Ruyangosaurus-giganteus-Mk-II-712420775
www.deviantart.com/randomdinos/art/Patagotitan-mayorum-skeletal-reconstruction-762150985
Hocknull, Scott A.; White, Matt A.; Tischler, Travis R.; Cook, Alex G.; Calleja, Naomi D.; Sloan, Trish; Elliott, David A. (2009). Sereno, Paul (ed.). "New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia"
www.deviantart.com/megalotitan/art/Paludititan-MK-III-745180274
Seebacher, F. 2001. A new method to calculate allometric length-mass relationships of dinosaurs. Journal of Vertebrate Paleontology 21
www.deviantart.com/scotthartman/art/Opisthocoelicaudia-750970320
van Valen, Leigh (1969-08-29). "What Was the Largest Dinosaur?"

*Yes, I know that GDI says Saltasaurus is 8.55 meters and 1.9 tonnes instead of 8 meters and 2.5 tonnes. That's because it is not Greg Paul's, but I couldn't find a GDI table for Paul's and the proportions between the stand-in vs what I'm using as a base should be similar enough. Reply