Some 130 million years ago, a spike-backed dinosaur walked heavily through the wilderness of what came to be Australia, and left its footprints as a gift for the future. They were the world’s best impressions of a dinosaur’s two-ton footfalls. When they were found seven years ago in a remote valley in northern Australia, they provided scientists with the first clear evidence that dinosaurs had lived in Australia. This discovery provided further evidence for the theory that Australia was once joined to a vast super-continent that included what is now South America, Africa, India and Antarctica.