DESCRIPTION: A few years ago in the Argentinian desert, a shepherd was searching for one of his lost sheep when he spotted the tip of a gigantic fossil bone sticking out of a rock. When the news reached paleontologists at the Museo Egidio Feruglio, a museum in Patagonia, they set up camp at the discovery site to examine it and look for more bones. The first bone turned out to be an eight-foot-long thighbone, the largest ever found. This started an investigation that would take over two years to complete. By the end of the dig they had uncovered more than 220 bones. As the program reveals, these fossils came from not just one dinosaur but seven, all belonging to a new species of giant plant-eating "titanosaur," which is yet to be given its own scientific name. Sir David Attenborough takes us through the twists and turns of this forensic investigation, in a bid to find out more about this new dinosaur. He talks to the paleontologists studying the fossils along with comparative anatomy experts and looks at what the bones reveal about the lives of these dinosaurs - each estimated to weigh an equivalent of 15 African elephants. With the help of 3D scanning, CGI visuals, and animation, the completed dinosaur giant is unveiled, the largest creature ever to roam the Earth!