"Henry Fairfield Osborn's Lizard Crest"
Length: 9.8m (32ft)
Weight: 1.9 tonnes (2.1 tons)
Location: Alberta, Canada
Era: Maastrichtian age, upper Cretaceous (69 million years ago)
S. osborni, the type species of the Saurolophus genus, is actually noticeably smaller and much rarer than the Asian S. angustirostris. Uniquely, both species are known from skin impressions, which indicate that the two species may be diagnostic based on scalation.
UPDATE FEB 5, 2013:
It had come to light after I had done all of the Hadrosaurids in my project that they actually could not pronate their hands, so I have updated Saurolophus accordingly.