FYI.

This story is over 5 years old.

The Largest Dinosaur Ever Unearthed May Not Actually Be the Largest

Either way, we're going to need a bigger museum.
May 20, 2014, 6:55pm
Researcher Pablo Puerta next to the titanosaur's femur. Image: José María Farfaglia and Museo Paleontológico Egidio Feruglio

Paleontologists based out of Argentina's Museo Paleontológico Egidio Feruglio have discovered what is quite possibly the largest known animal ever to walk the Earth. The new species of titanosaur, as yet unnamed, is estimated to have weighed 77 tons and measured 120 feet long, making it as tall as a seven-story building. You know you're dealing with a true giant when it makes other sauropods look small in comparison.

Even more exciting is the sheer number of specimens recovered from the dinosaurs' final resting place on the La Flecha farm in Patagonia. Over 200 fossils have been found on the farm, representing at least seven individuals from this record-breaking species. On top of that, only 20 percent of the quarry where the fossils were found has been excavated, and researchers expect to find many more specimens in the coming years.

Advertisement

“What they discovered is a cemetery of dinosaurs the likes of which we had never seen in the history of Argentine paleontology," said Ruben Cuneo, director of the Museo Paleontológico Egidio Feruglio, to US News. “Given the length and magnitude this animal will bring along when it's reconstructed, there won't be a building that can contain it. I think we're going to need a new home.”

The dig team, led by paleontologists Diego Pol and Jose Luis Carballido, concluded that the titanosaur remains were probably not transported into the quarry by rivers or other natural forces. Instead, the sauropods may have selected an isolated Late Cretaceous flood plain for their last moments, in the same way that dying elephants occasionally seek out comforting grave sites.

There's also evidence that later on, the sauropods were pulled apart by marauding theropod dinosaurs. Over 50 teeth from the massive carnivore Tyrannotitan chubutensis were also discovered at the site, suggesting that some lucky scavengers had the feast of a lifetime 95-100 million years ago.

If new species has edged Argentinosaurus as the previous record holder for world's largest land animal, but both may have been dwarfed by the mysterious Amphicoelias fragillimus. Based on descriptions of a single fossil, Amphicoelias could have weighed 135 tons, almost twice as much as this freshly discovered sauropod.

The estimated size of Amphicoelias in red. Image via Matt Martyniuk.

But the story behind this animal is somewhat suspect. An Amphicoelias vertebrate and femur were discovered in 1877 at the height of the Bone Wars, but the specimens were somehow lost in the subsequent decades. All modern paleontologists have to go on are the notes of the legendary fossil hunter Edward Drinker Cope. Studying an animal secondhand is obviously not ideal, and Amphicoelias is usually excluded from the list of biggest dinosaurs based on lack of evidence.

Along those lines, some paleontologists think the new titanosaur needs to be subjected to more scrutiny before it is proclaimed the biggest land animal ever. "Whether or not the new animal really will be the largest sauropod we know remains to be seen," said Paul Upchurch, a paleontologist at the University College of London, to ABC News.

"Certainly the new animal appears to be at least as large as Argentinosaurus, and is a new species," he said. "Its real scientific value comes from the fact that it looks like this new form will be more complete than Argentinosaurus, so we'll get a better look at the anatomy of one of these super-giants."

And as Brian Switek explained, "Even sauropods known from a decent amount of material are still too incompletely known to get a direct idea of how long and heavy they were."

So while dinophiles around the world are right to celebrate this momentous find, it's important to always say “for now” with record-breaking dinosaurs. The new titanosaur may be the top dog in 2014, but no doubt there are plenty of mind-boggling species that have yet to be unearthed.