Among the new animals in the new installment of the Jurassic saga, Jurassic World Dominion , are creatures of all kinds. From small-sized dinosaurs, such as Moros , to the largest carnivore that has walked the earth, Giganotosarus ; feathered raptors, synapsids like Dimetrodon , or the largest animal that has crossed the skies: Quetzalcoatlus .
Of all of them, Dreadnoughtus stands out, the first identified by Professor Grant from the plane and the largest animal seen so far in the Jurassic saga. .
A South American Titan
Dreadnoughtus schrani was discovered in Patagonia, Argentina and first described by a team of paleontologists led by Kenneth J. Lacovara, in a 2014 publication in the Nature -dependent journal Scientific Reports .
In this study, the researchers point out that up to 70% of the dinosaur’s postcranial skeleton had been found, something exceptional for a titanosaur —literally ‘titan lizards’, the group of dinosaurs to which Dreadnoughtus belongs. Most of the dinosaurs larger than 40 tons in this group are represented by highly fragmented fossils, with the exception of Futalognkosaurus , of which much of its vertebral column and pelvis were found. This makes Dreadnoughtus the titanosaur with the most complete skeleton known to date.
discussions about its size
In the latest installment of the Jurassic saga we are introduced to a really huge dinosaur, although at no time do you get to see something close enough to serve as a size reference.
When the size of its bones is compared to those of other large dinosaurs, it is found that Dreadnoughtus generally outperforms most. Only Giraffatitan and other brachiosaurids surpass it in foreleg length, which is to be expected: titanosaurs such as Dreadnoughtus had similarly long forelegs and hindlegs, while brachiosaur forelegs were longer than their hind legs. Regarding these, the fibula bone of Argentinosaurus , another titanosaurid, is longer than that of Dreadnoughtus . When the complete skeleton is observed, the length of this animal is estimated at about 26 meters.
Through a series of mathematical calculations that relate the diameter of the femur and humerus to weight, Lacovara and his collaborators determined that Dreadnoughtus must have weighed about 59 tons, well above the largest of the brachiosaurids – Giraffatitan is around 34 tons – and up to four times more than Diplodocus , a dinosaur that, although lighter, exceeds it in length with 33 meters. It is a dinosaur that weighs the equivalent of nine male African elephants.
However, this weight has been questioned. Using volumetric techniques, in which the volume of the animal is calculated and from there, the weight is estimated from a hypothetical density, the paleontologist Gregory Paul even stated, in 2014, that Dreadnoughtus did not exceed 26 tons. Later calculations, in 2019, made by the same author and following the same method, placed it at around 31 tons. And another study, from 2020, by Alejandro Otero and collaborators, again using bone measurement techniques, but with more modern equations, once again raised its weight to 49 tons.
That different values are obtained using different weight estimation techniques should not surprise anyone; growth is not always homogeneous, nor do animals all have the same density. However, obtaining different values using the same techniques is a sign of low reliability of the calculations or of a lack of sufficient data. The discussion about Dreadnoughtus mass is probably not over yet, and it would not be surprising if new publications continue to correct the values until a stronger consensus is reached.
The longest of the Jurassic saga
Throughout the five films we have had the privilege of seeing four sauropods – the long-necked dinosaurs – competing to be the largest.
In the second installment, The Lost World , during the stampede we could see a pair of Mamenchisaurus . As far as we know, these animals have the longest neck in the animal kingdom. However, they make up for it with a short, massive body and a not very long tail, their total length does not exceed 20 meters.
Slightly longer is Apatosaurus , seen in all three Jurassic World installments, and measuring about 21 meters in length. And longer still was the saga’s most iconic sauropod, Brachiosaurus , the first dinosaur visitors saw upon arrival on the island, seen on the big screen in Jurassic Park , Jurassic Park III and Jurassic World Fallen Kingdom .
At 26 meters in length, Dreadnoughtus is therefore the longest dinosaur we have seen in the entire Jurassic saga.
References:
Lacovara, K. J. et al. 2014. A Gigantic, Exceptionally Complete Titanosaurian
Sauropod Dinosaur from Southern Patagonia, Argentina. Scientific Reports, 4(1), 6196. DOI: 10.1038/srep06196
Otero, A. et al. 2020. The Appendicular Osteology of Patagotitan Mayorum (Dinosauria, Sauropoda). Journal of Vertebrate Paleontology, 40(4), e1793158. DOI: 10.1080/02724634.2020.1793158
Paul, G. 2014. Not so gigantic after all: Response to Lacovara et. al. Figshare.
Paul, G. 2019. Determining the Largest Known Land Animal: A Critical Comparison of Differing Methods for Restoring the Volume and Mass of Extinct Animals. Annals of Carnegie Museum, 85(4), 335-358. DOI: 10.2992/007.085.0403
