 The 1914 publication of the arch @-@ snouted Canadian genus Gryposaurus changed Brown 's mind about the anatomy of his dinosaur 's snout . Going back through the fragments , he revised the previous reconstruction and gave it a Gryposaurus @-@ like arched nasal crest . He also synonymized Gryposaurus with Kritosaurus , a move supported by Charles Gilmore . This synonymy was used through the 1920s ( William Parks 's designation of a Canadian species as Kritosaurus incurvimanus , now considered a synonym of Gryposaurus notabilis ) and became standard after the publication of Richard Swann Lull and Nelda Wright 's 1942 monograph on North American hadrosaurids . From this time until 1990 , Kritosaurus would be composed of at least the type species K. navajovius , K. incurvimanus , and K. notabilis , the former type species of Gryposaurus . The poorly known species Hadrosaurus breviceps ( Marsh , 1889 ) , known from a dentary from the Campanian @-@ age Judith River Formation of Montana , was also assigned to Kritosaurus by Lull and Wright , but this is no longer accepted . 
