OSAKA They were the biggest of the big. With their long necks and tails, the sauropod subgroup of dinosaurs comprised the largest animals ever to roam on land, scientists say. Many grew to more than 20 meters in length and weighed over 10 tons. A few years ago, paleontologists discovered the fossil of a beast that was an estimated 40 meters long and weighed around 80 tons.
The staggering size of these dinosaurs raises a question: How did they grow so big in the first place? Researchers say the answer lies in a number of special characteristics, including unique, fast-growing bones.