Many species of dinosaurs have been discovered at Hermiin Tsav in the Gobi Desert over the years, but now there is something new to describe: the first swimming dinosaur. The creature was not a giant but a foot-long streamlined beast, with long jaws full of tiny teeth. The theropod, or hollow-bodied dinosaur, had three toes and claws on each limb and swam in prehistoric Mongolia 145 to 66 million years ago when there were lakes and rivers. Seoul National University paleontologist Sungjin Lee and colleagues have named the dinosaur Natovenator polydontus, the “many-toothed swimming hunter.”