It's a good job it's not walked the Earth for 110 million years - because if it was around today, a new species of Dinosaur might be a little offended.
That's because the scientists that discovered it have named it 'Thunder Thighs'!
The new Dino fossils were found in America - and researchers noticed it was a new species, and it had HUGE leg muscles.
So they called it Brontomerus mcintoshi - which is Greek for "thunder" and "thigh". Check out the video of how they think it would have looked!