What If Styxosaurus Was Alive?

You pop out of the ocean and hear the faint yells of the lifeguard. The whole beach panics. Your turn around. Something lurks in the water. Before you can say "Loch Ness monster," a tall shadow emerges, lunging with its sharp teeth headed your way. If the Styxosaurus were around today, where would it live? What would your potential demise have to do with being crushed by stones? And why could it be more afraid of you than you'd be of it?