Bactrosaurus (meaning "Bactrian lizard," "Bactria" + sauros = lizard) was a herbivorous dinosaur that lived in east Asia during the late Cretaceous, 97 - 85 Ma. The position Bactrosaurus occupies in the Cretaceous makes it one of the earliest known hadrosaurs, and although it is not known from a full skeleton, Bactrosaurus is one of the best known of these early hadrosaurs, making its discovery a significant finding.