A completely articulated ichthyosaur skeleton from the Guanling biota, Guizhou Province is described. The well preserved postcranial skeleton demonstrates that Guizhouichthyosaurus tangae, a large Triassic ichthyosaurid species previously described from Guizhou Province, should be referred to Shastasaurus. Enough materials were found to make possible a satisfactory determination of the systematic position of the large Guanling ichthyosaur species, although both the genus Shastasaurus and the family Shastasauridae have long been hard to define due to the fragmentary nature of the type specimens. The postcranial characters of Shastasaurus tangae are described in detail based on the new skeleton, the holotype of Guizhouichthyosaurus tangae and other associated Guanling large ichthyosaur materials.