Scientists have unveiled estimates of body weight for an astounding 426 dinosaur species using a formula based on the thickness of their leg bones, crowning the long-necked Argentinosaurus as the all-time heavyweight champ.

That plant-eating dinosaur weighed an earth-shaking 90 tons when it lived about 90 million years ago in Argentina. It is the largest known land creature in the planet's history. Blue whales, the largest animals ever, can weigh up to 170 tons.

"Argentinosaurus, that's the champion," Oxford University paleontologist Roger Benson, who led the study, said in an interview. "It's colossal."