The world's largest dinosaur: the 'Patagotitan' mayorum

After several years of anonymity, the world's largest titanosaurus was baptized in August 2017. A study published in the journal Proceedings of the Royal Society B collected its name, Patagotitan mayorum, and details about its anatomy. The dinosaur weighed about 70 tons and was almost 40 meters long. When it raised its neck, it could reach a height similar to the seventh floor of a building.

This giant from the distant past, which commands great respect, was discovered in the Province of Chubut in 2013 and its name, Patagotitan mayorum, is due to "Patago" for Patagonia; "titan" for the Greek deities and "mayorum", in honour of the Mayo family, the owners of the "La Flecha" ranch where the unheard of fossils were found.

Among the details revealed in the study of the six specimens discovered, the researchers were able to determine that this giant, weighed the equivalent of 14 African elephants, 69 tons and was 39.5 meters long as if we put two tow trucks, one behind the other.

The legendary Tyrannosaurus rex "look like dwarfs when you put them next to these giant titanosaurs. It's like when you put an elephant next to a lion," explained Diego Pol, co-author of the paper.

Examining these fossils was an interesting task for the experts involved since it is not often that titanosaur fossils are found, much less that they are found in good condition. The remains of 'LaFlecha' had both of these unusual qualities.

"By the second campaign, we had already realized that the bones that were appearing corresponded to different individuals of the same species, who had died at different times, perhaps several years apart. Analyzing the bones, we were struck by the fact that all the individuals were adult animals, but young. They were still growing slowly. If you had to compare them to a human, it would be an 18-year-old person," explained study co-author Jose Luis Carballido.

Kristi Curry Rodgers, a palaeontologist at Macalester College who was not part of the study, praised the work, saying that the fact that the Patagotitan's bones show signs of not having completed their growth "means that there are even bigger dinosaurs out there undiscovered.

One of the interesting things that the palaeontologists point out is that they believe that, despite the enormous length of the dinosaur's neck, it is most likely that the dinosaurs walked around with their necks parallel to the ground in order to feed themselves without making much effort with their bodies (unlike giraffes).

The skull of the Patagotitan mayorum is an unknown quantity. Not in vain, it is the most difficult piece to find in many sauropods and especially in titanosaurs. "We only found one tooth of these animals in the shape of a spoon," said Pol

Why were these dinosaurs so big?

Cretaceous. 101 million years ago. South America, a region inhabited by dinosaurs that evolved independently from the rest of the world. "Other very large species of approximately the same age have been found in Patagonia and one of the things we discovered is that these giants were very closely related to each other, they belong to the same clade -a grouping that contains a common ancestor and all its descendants-", explained Diego Pol. "This indicates that something special happened so that these species developed extreme gigantism. This Patagonian family broke the mould".

The big question is how these dinosaurs got so big. One of the hypotheses being considered has to do with the environmental changes that took place in that area and which led to a more diverse and abundant flora, which means more available food resources. 

A full-scale replica of the Patagotitan can be seen at the American Museum of Natural History in New York City from early 2016. (USA) of such a great dinosaur.

Reference: Carballido JL, Pol D, Otero A, Cerda IA, Salgado L, Garrido AC, Ramezzani J, Cúneo NR, Krause MJ. 2017. A new giant titanosaur sheds light on body mass evolution amongst sauropod dinosaurs, Proceedings of the Royal Society B, August 2017.DOI: 10.1098/rspb.2017.1219