I often see Nyctosaurus recontructions that either have a distinct Y-shaped crest or a crest with keratin in between the 2 points (like Tupandactylus). This Nyctosaurus' crest is somewhat in-between. Next I'll be drawing a Pliosaurus reconstruction.

I usually base these drawings on skeletal diagrams by Scott Hartmann, but here, I used a skeletal diagram by Gregory S. Paul. Thank you @Ganimes for finding this skeletal diagram.