Do you feel like you have a good grasp of what you think the biggest dinosaur is? Tyrannosaurus rex, you say? You’re so stupid. A T. rex isn’t even as big as the dinosaur paleontologists thought was the biggest until they recently found the dinosaur that is the biggest. But now they know the dinosaur that really is the biggest.
In 2013, scientists led by researchers from the Museum of Paleontology Egidio Feruglio (MEF) in Argentina discovered some new dinosaur bones. The bones were remarkable not only for their size (really big), but also for their astonishingly well-preserved condition.
The Titanosaurs are a diverse group of long-necked, herbivorous dinosaurs that walked on four legs. The smallest of them was roughly the size of an elephant. The largest of them is this new species discovered with the best-preserved remains of any species in the lineage.
With their long necks, long tails, four legs, and plant-based diet, you may think the Titanosaurs closely resemble sauropods like Brontosaurus, Apatosaurus, Brachiosaurus and Diplodocus. But you're wrong. They’re different.
How are they different? Let Dr. Carballido explain. He says, “They have some anatomical characteristics, especially on the tail vertebrae and on the hip bones, that share among themselves and differentiate them from the rest.”
Scientists know this new dino was damn big, but guessing its weight isn’t an exact science. “We only have left the bones and from these remains we have to infer the body weight through the use of indirect methods,” said MEF specialist Diego Pol. But researchers’ best guess is that it weighed around 70 tons, which is like 10 African elephants, which, whoa.
After four years and more than 200 new bones of the species, scientists have finally given the new biggest dinosaur a name: Patagotitan mayorum. “Patagotitan” comes from where it was found (Patagonia), and “mayorum” is for the Mayo family, on whose La Flecha Farm scientists discovered the fossils.
The sheer size of Patagotitan is exciting for casual dino fans like us, but for paleontologists, it’s really the quality of the bones that’s the headline here. “The most amazing moment for us was realizing that the dinosaur is not only large, but also more complete than any other titanosaur,” Dr. Carballido told The Atlantic. And that means a whole new world of discovery for scientists who study the Titanosaur lineage.
In roughly third place is the Puertasaurus, which is just slightly smaller than Argentinosaurus, probably, based on researchers’ wild estimates. Like Patagotitan and Argentinosaurus, Puertasaurus is also a Titanosaur, also discovered in Patagonia.
Close behind Puertasaurus comes the absurdly named Futalognkosaurus, which means "giant chief lizard.” Well, “chief” except for the three dinosaurs bigger than it. Would it surprise you to learn that Futalognkosaurus is a Titanosaur discovered in Patagonia? It shouldn’t, guys. Learn to follow patterns.
Look, here’s the real truth: Estimates of these Titanosaurs' size and weight is very rough, and they’re so close together that, for all intents and purposes, it’s a multi-way tie for the title of “biggest dinosaur.” What’s important is that they all dwarf Tyrannosaurus rex. They make that pinhead look like a bozo.
OK, OK, but who’s the smallest of the biggest? In other words, what’s the smallest dinosaur in the Titanosaurus lineage? That would be the Magyarosaurus. This puny loser measured only 5 or 6 meters, and weighed barely more than a ton. Why was the Magyarosaurus so small? The species were island dwellers, and a small habitat equals a small dinosaur.