An ichthyosaur rostrum from the uppermost Albian of Saskatchewan (Canada) represents the youngest diagnosable Canadian ichthyosaur prior to their demise
Dirley Cortés, Hans C.E. LarssonA partial ichthyosaur rostrum from Albian-aged Ashville Formation deposits in southern Saskatchewan is described here. Previously referred to Platypterygius americanus, the well-preserved rostrum includes the snout tip and several articulated teeth. Based on the unique anteroventral curvature of the snout and proportions of the premaxilla, dentary, and teeth, the specimen is reaffirmed as P. americanus with diagnostic traits in spite of the lower Cenomanian age for the type and previously referred material for this taxon. The Saskatchewan specimen extends P. americanus to the late Albian, and the species would have inhabited the Western Interior Seaway along with other marine predators with varied diets. The teeth of the Saskatchewan specimen are generalist in morphology due to their large size and robust crows. Further research is required to shed light on ichthyosaur snout anatomy and evolution immediately prior to their extinction by the Late Cenomanian.