Bones reveal new dinosaur species

A Tarbosaurus from Mongolia (L) is seen next to the world's largest Tyrannosaurus Rex, named Sue, is seen at the Dinosaur Expo 2005 after it's assembly was completed at the National Science Museum on March 16, 2005 in Tokyo, Japan. Fossil hunter Sue Hendrickson discovered Sue in 1990 and the Field Museum in Chicago purchased Sue at public auction in 1997.

An new dinosaur species, what may be one of the largest ever discovered, was officially named Thursday. It's called Dreadnoughtus schrani.

An new dinosaur species, what may be one of the largest ever discovered, was officially named Thursday in a paper published by the journal Scientific Reports. It's called Dreadnoughtus schrani.

About 70 percent of the dinosaur's skeleton could be reconstructed with bones found in Southern Argentina in 2005.

"The prefix 'dread' might make it sound like a terrifying predator, but this was more of a gentle giant," says National Geographic writer Brian Switek. "Overall, this animal would have been about 86 feet long and 60 tons, so this is a pretty heft dinosaur."

Switek said Dreadnoughtus schrani is believed to have lived at the very end of the dinosaur reign and is one of the last great giants.