In 1959 and 1960 a Soviet-Chinese expedition uncovered the remains of a euornithopod in Inner-Mongolia near Moartu. The type species is Probactrosaurus gobiensis, described and named by A. K. Rozhdestvensky in 1966. The generic name refers to Rozhdestvensky's hypothesis that Probactrosaurus would be the direct ancestor of Bactrosaurus, a notion today discarded. The specific name refers to the Gobi desert. The holotype specimen, PIN 2232/1, a partial skeleton with skull, was found in layers of the Dashuigou Formation. Another partial skeleton was found, PIN 2232-10, along with numerous other fragments.[1]