Earlier we looked at Pteranodon skulls all to the same scale and in phylogenetic order. Today there’s a GIF movie that presents the same data (Fig. 1).

Figure 1. Click to animate. Pteranodon skull movie. All the skulls are to the same scale and in phylogenetic order. Each skull appears for 2 seconds and the animation recycles when the page is reloaded. And yes, the long-crested clade does terminate with three smaller taxa.
The first tiny specimen is actually an outgroup Germanodactylus. Long crests and great size evolve from small crests and small size. Learn more about Pteranodon variety here.
Long-crested taxa had digitigrade feet. Tall-crested taxa had flat feet. Other postcranial differences are discussed here.