Paleontologists say several hundred fossilized footprints in a Beijing suburb are those of dinosaurs. The footprints, unearthed in a geological park in Yanqing county, are the first dinosaur traces the city has found, according to Zhang Jianping, researcher at the China University of Geosciences. They were left by dinosaurs that lived some 140 to 150 million years ago in the late Jurassic period, said Zhang. A group of scientists from Zhang\'s university first discovered the footprints in July 2011 in the Guihuamu Geological Park, which is known for its concentration of petrified ancient woods. In one spot where most of the footprints are concentrated, the paleontologists counted several hundred footprints as well as seven to eight lines formed by consecutive steps. Thyreophoras, theropods, ornithopods, and probably sauropods are believed to have left the footprints. The discovery will benefit the study of China\'s dinosaur categories at late Jurassic and early Cretaceous periods, Zhang said. \"It\'s the first time China has found thyreophora, ornithopod, and sauropod footprints of that period, which provides us with more knowledge on how such species spread across China,\" said Zhang.