These creatures have yet to be given a name, but they belong to a group known as Titanosaurs. They had long necks and tails and are claimed by those who discovered them to have been the largest creatures ever to have walked the Earth. At full stretch, they were the height of a seven-storey building and weighed more than ten full-grown elephants. Yet they were probably not fearsome, but mild-mannered vegetarians.
The giant dinosaurs lived 100 million years ago, in what is now Patagonia. Dr Bill Sellers, a palaeontologist at the University of Manchester, says it's a very exciting discovery:
"This is an amazing find because they've got so many dinosaurs there. I mean, this is seven individuals and these things are enormous! And actually it's really important because we don't know very much about these. We actually have very very few complete skeletons, and it looks like they've got quite a lot of bones here. So I think we will be able to piece together what's a real animal rather than a sort of composite."
So far more than 200 bones have been found. The discovery should increase our understanding of how these magnificent creatures evolved.