In 1972, a second species Young and Xijin Zhao described "Mamenchisaurus hochuanensis". The fossils were found near a village in Hechuan, north of Chongqing (originally part of the Sichuan Province), China; above the Fu River on the slope of a mountain. The "M." "hochuanensis" fossil site also belonged to the Upper Shaximiao Formation, very close to the "M. constructus" type specimen's location, dating to at least the Late Jurassic. Locals first discovered the remains sometime before the Chinese Revolution. However, the remains were ultimately abandoned and left to weather in situ. Excavation didn't begin on the site until 1957.