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Has anybody figured out the exact systematic placement of Stephanosaurus marginatus? As far as I can recall, the holotype of S. marginatus (CMN 419) consists of bones of the forelimb and the foot as well as fragments of neck vertebrae, teeth, and ribs (disassociated bones cataloged under CMN 419 [including a theropod ischium] were provisionally referred to T. marginatus by Lambe 1902, but were later referred to Lambeosaurus by Gilmore 1924). The two editions of the Dinosauria list Stephanosaurus and its type species as a nomen dubium (probably based on the assessment of Stephanosaurus as gen. et. sp. indet. in Brett-Surman's 1989 thesis), but without comment. As pointed out by Gilmore (1924), Stephanosaurus differs from Gryposaurus notabilis only in that the humerus and radius are almost equally proportional to each other in length (ratio of humerus length to radius length in Stephanosaurus 1:0.953 versus 1:0.881 in Gryposaurus notabilis) and the radius and ulna are larger than those of Gryposaurus. Since mid-late Campanian of Montana and Canada is starting to become crowded with saurolophines belonging to different tribes (Brachylophosaurini, Kritosaurini, Saurolophini) and no edmontosaurins have been found in the Dinosaur Park Formation yet, I'd be curious to see if Stephanosaurus could be its own thing or not.