ABSTRACT Although Mesozoic fossils are quite common in the Gobi Desert of Central Asia, it is often difficult to correlate among different localities because of a dearth of rocks amenable to absolute dating. Specifically, correlating between the eastern Gobi Desert and more western localities has been challenging. Here we give a Santonian-Campanian age for the enigmatic Zos Canyon beds in the Nemegt basin. This is based on the occurrence of the primitive ornithopod dinosaur Haya griva at both eastern Gobi exposures of the Javkhlant Formation and the Zos Canyon locality.