O. arharensis shared its time and place with several other types of animal, including two other lambeosaurines: the Parasaurolophus-like Charonosaurus and more basal Amurosaurus. Additionally, remains from turtles, crocodilians, theropods, and nodosaurids were found at its discovery site,[2] and the Saurolophus-like hadrosaurine Kerberosaurus is also known from roughly contemporaneous rocks in the area.[4] Unlike the situation in North America, where lambeosaurines are essentially absent from Late Maastrichtian rocks, Asian lambeosaurines are diverse and common at the end of the Mesozoic, suggesting climatic or ecological differences.[2]