Dinosaur size

 ( Animal Size ) 

Another large but even more controversial sauropod is Bruhathkayosaurus, which had a calculated weight ranging between and a length of Mortimer, M. (2001), "Re: Bruhathkayosaurus", discussion group, The Dinosaur Mailing List, 19 June 2001. Accessed 23 May 2008.Mortimer, M. (2004), "Re: Largest Dinosaurs" , discussion group, The Dinosaur Mailing List, 7 September 2004. Accessed 23 May 2008.Mortimer, M. (2001), "Titanosaurs too large?" , discussion group, The Dinosaur Mailing List, 12 September 2001. Accessed 23 May 2008. Although the existence of this sauropod had long been dismissed as a potential fake or a misidentification of a petrified tree trunk, recent photographic evidence emerged, confirming its existence. More recent and reliable estimates in 2023 have rescaled Bruhathkayosaurus to weigh around with its most liberal estimate being , making it incredibly massive for such an animal. If the upper unlikely size estimates were to be taken at face value, Bruhathkayosaurus would not only be the largest dinosaur to have ever lived, but also the largest animal to have lived, exceeding even the largest blue whale recorded. According to Gregory S. Paul, 'super-sauropods' or 'land-whales' such as Maraapunisaurus, Bruhathkayosaurus and the "Broome Titanosaur footprints," as he calls them, should not be surprising as sauropods were more heat tolerant and grew rapidly, which allowed them to reach truly titanic sizes that rivaled the largest whales in mass despite the prevalence of air sacs. Other potential factors for such extreme sauropod sizes include increasing bone robustness and load-distributing cartilaginous features to better redistribute and support such massive weights.

Generally, the giant sauropods can be divided into two categories: the shorter but stockier and more massive forms (mainly and some Brachiosauridae), and the longer but slenderer and more light-weight forms (mainly ).

Because different methods of estimation sometimes give conflicting results, mass estimates for sauropods can vary widely causing disagreement among scientists over the accurate number. For example, the titanosaur Dreadnoughtus was originally estimated to weigh 59.3 tonnes by the allometric scaling of limb-bone proportions, whereas more recent estimates, based on three-dimensional reconstructions, yield a much smaller figure of 22.1–38.2 tonnes. The Sauropoda were the longest and heaviest dinosaurs. For much of the dinosaur era, the smallest sauropods were larger than almost anything else in their habitat, and the largest were an order of magnitude more massive than anything else known to have walked the Earth since. Giant prehistoric such as Paraceratherium and Palaeoloxodon (the largest land mammals ever discovered) were dwarfed by the giant sauropods, and only modern whales approach or surpass them in weight, though they live in the oceans. There are several proposed advantages for the large size of sauropods, including protection from predation, reduction of energy use, and longevity, but it may be that the most important advantage was dietary. Large animals are more efficient at digestion than small animals, because food spends more time in their digestive systems. This also permits them to subsist on food with lower nutritive value than smaller animals. Sauropod remains are mostly found in interpreted as dry or seasonally dry, and the ability to eat large quantities of low-nutrient browse would have been advantageous in such environments.Carpenter, K. (2006). "Biggest of the big: a critical re-evaluation of the mega-sauropod Amphicoelias fragillimus." In Foster, J.R. and Lucas, S.G., eds., 2006, Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin 36: 131–138.

One of the tallest and heaviest dinosaurs known from good skeletons is Giraffatitan (previously classified as a species of Brachiosaurus). Its remains were discovered in Tanzania between 1907 and 1912. Bones from several similar-sized individuals were incorporated into the skeleton now mounted and on display at the Museum für Naturkunde Berlin;

In 2014, the fossilized remains of a previously unknown species of sauropod were discovered in Argentina. The titanosaur, named Patagotitan mayorum, was estimated to have been around long weighing around , larger than any other previously found sauropod. The specimens found were remarkably complete, significantly more so than previous titanosaurs. It has since been suggested that Patagotitan was not necessarily larger than Argentinosaurus and Puertasaurus. In 2019, Patagotitan was estimated to have been long and about .

The largest of non-sauropod Sauropodomorpha was the unnamed long unnamed Elliot giant. Another large sauropodomorph was Euskelosaurus. It reached in length and in weight.