The Plesiosaur Body Shape and its Impact on Hydrodynamic Properties
Anonymous (noreply@blogger.com)
Cryptoclidus' torso is unusually steep-sided for a Plesiosaur and it indicates some better degree of vertical movement at the surface, for surfacing, poking its head up, and then going straight down again.
The Saint-Fancois-Xavier sighting evidently has the animal showing a rear fin as it rolls and here is a version of the Plesiosaur in that position: