While the Late Cretaceous dinosaur faunas of southern and northern Alberta, Canada, are well studied, comparable faunas of central Alberta are more poorly known. Herein is described a new occurrence of the lambeosaurine hadrosaurid Hypacrosaurus altispinus from the Horseshoe Canyon Formation in Leduc, Alberta. The skull of this specimen is well preserved, allowing its identification as the northernmost-known occurrence of this taxon. This specimen preserves an unusual, possibly paedomorphic feature of the premaxilla, as well as a keratinous beak and two modes of scale preservation. The addition of this specimen to the known sample of H. altispinus reaffirms this derived cranial morphology of the species, calling attention to morphological separation between this species and “H.” stebingeri. Comparison of the skull and vertebrae of this specimen and other H. altispinus to other Lambeosaurinae reveals problematic past diagnoses for the genus Hypacrosaurus; crest dimensions, fontanelle closure, and neural spine height are non-diagnostic for this genus at present. “H.” stebingeri has a problematic history of study and may be a wastebasket taxon; the new combination Corythosaurus stebingeri is proposed.
Sharpe et al. (Wed,) studied this question.