Humanity knows that millions of years ago, dinosaurs ruled the earth.
But we didn't know the name of the biggest of them all — that is, until now.
Dreadnoughtus schrani, the largest land animal ever discovered, was publicly named at a ceremony at Drexel University Thursday as the remains were revealed.
This dinosaur was an estimated 85 feet long and 2.5 stories tall, weighing 65 tons. It's femur or thigh bone alone weighs 1,200 pounds; the humerus (upper arm bone) weighs 800 pounds.
"It had no possible predators. Nothing could ever mess with this dinosaur," said Drexel Professor Kenneth Lacovara, the lead paleontologist on the team that discovered these fossils in the forests of Patagonia on the southern tip of South America.
"It belongs to the world now," said Lacovara, before pulling back a cloak to reveal for the first time ever the Dreadnoughtus' tibia bone, to wild applause.
The genus Dreadnoughtus has never existed before and was created for this dinosaur, but it is a member of the long-necked, long-tailed titanosaur family, familiar to most lovers of dinosaurs.
"As we kept digging, we kept finding more and more," said paleontologist David Poole, of working the dig site in Argentina, which Lacovara discovered. "We were amazed at the amount of bones we were finding."
About 145 bones were discovered at the dig site by the team of scientists led by Lacovara, making up two Dreadnoughtus schrani, one slightly smaller and weighing about 30 tons, possibly a parent-child pair or pair of mates, according to members of the team.
The 115 bones which make up the 65-ton larger Dreadnaughtus account for 70 percent of the types of bones in the dino's skeleton, said paleontologist Matthew Lamanna, an unusually complete discovery which will help scientists study titanosaur's range of motion and weight support.
"It's big and that's awesome, but it's very complete, and that's what's more important," Lamanna said. "It's really one of our best windows into the anatomy of titanosaurs as a whole, rather than just the giant members of the group."