Though there were a number of massive dinosaur species, the largest of them all were the sauropods, which included the diplodocus and brontosaurus. They could grow to the size of 10 buses!
Now researchers have found an explanation for why this group of dinosaurs were so large – and why they had such long necks.
A team of palaeontologists studied a fossil found in Patagonia, South America. The fossil is one of the oldest sauropod fossils found.