Plesiosaur Evolution

A commenter recently pointed me to a (largely defunct) project about an alternate evolution for dinosaurs called Specworld, basically imagining what dinosaurs might have evolved into if it hadn't been for the whole extinction thing. I couldn't resist making my own contribution, so here it is. It's a hypothetical evolutionary path for the plesiosaur, having developed longer, wing-like flippers and a keel on the sides of its' head for quick direction changes while chasing fish.