The Biggest Dinosaur Ever: What We Know About Patagotitan

The biggest dinosaur ever found was a titanosaur from 100 million years ago that would have gotten even larger if it hadn’t died so soon.

Although scientific estimates have it weighing between 126,000 and 138,000 pounds and “it seems you are getting close to the maximal limit” of land animal size, paleontologist Diego Pol said, bone tissue from its fossils shows it had some room to grow.

He was speaking via Skype on Wednesday as the American Museum of Natural History in New York City unveiled the new name of the largest titanosaur ever: Patagotitan mayorum.

Read: Paleontologists Finally Found the Rest of a Famous Dinosaur Fossil

Since its discovery in 2012, paleontologists have been working to classify and understand the dinosaur. They have finally described it scientifically, in a study in the journal Proceedings of the Royal Society B: Biological Sciences, and given it a name.

The fossils’ story has a humble beginning: “A rancher in the middle of Patagonia was looking for sheep … and he saw something on the ground,” according to Pol, one of the authors of the study. It was the tip of a femur sticking up out of some rock. When paleontologists arrived to dig it up, they “ended up finding … over 150 bones of a brand new species, which happened to be gigantic.”

The name Patagotitan mayorum pays tribute both to the region where the giant was discovered and the Mayo family that owns the ranch where it was found.

There were actually six of the Patagotitan dinosaurs at the site, and together their bones show their kind was about 122 feet long. As far as scientists know they were the biggest land animal ever — some dinosaur fossils are more fragmentary remains than others, and the less complete a skeleton the more difficult it is to determine the animal’s full size.

Just like the rest of the titanosaurs, Patagotitan is a type of sauropod, the large dinosaur group known for having super long necks holding up their small heads and equally long tails. The long necks helped the herbivores reach vegetation that was high up, similar to the function of a giraffe neck in the modern animal kingdom.

Danny Barta, a paleontologist who helped the AMNH unveil the new dino name, explained that titanosaurs hatched from eggs that could be the size of a grapefruit, so to start off life so small meant they had to grow quite quickly.

“They really went crazy,” Pol said, calling them “supergiant.”

On top of being the largest titanosaur, the Patagotitan differs from most other titanosaurs in one other visual aspect: fashion. Pol said it is unlikely this enormous species had spikes and armor because of all the dozens of bones the paleontologists excavated — including from the neck, torso and tail — there wasn’t any trace of that armor.

We also know something about their lives beyond just their appearance. The six dinosaurs whose remains were found on the Mayo ranch died in the same spot at three different times. That says something about their behavior, according to Pol: They were probably returning to the same spot for a source of water or vegetation.

Read: 3D Tech Reveals Secrets of Old Dinosaur Fossil

But the exact circumstances remain a mystery that the paleontologist and his colleagues are working to understand. The biggest titanosaurs all lived in the same region around the same time.

Barta referred to the Patagonia of 100 million years ago as the “land of giants.”

Researchers want to know what it was about Patagonia during the Cretaceous period that allowed these dinosaurs to evolve into the massive creatures they were.

The study notes, “Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade.”