Keichousaurus another small aquatic reptile, lived over 200 million years ago during the Triassic Period. During this period, dinosaurs first started to rule the Earth. Keichousaurus skeletons come from China, a country that is famous for its exceptional fossils. When the people of ancient China first began to discover fossils of dinosaurs and other unfamiliar animals, they believed that they were dragon bones. The Keichousaurus was a very small creature, generally reaching just over a foot in length. We currently carry fossils of Sinohydrosaurus, also known as Hyphalosaurus, which looks like a smaller Keichousaurus. Sinohydrosaurus fossils are also found in China, but are much younger, dating back to the Cretaceous Period about 122 million years ago.