We know of at least three partial skulls of Quetzalcoatlus sp. (Kellner and Langston 1996), the smaller version of Q. northropi (Lawson 1975), for which no skull is known. This is how Kellner and Langston (1996) reconstructed the skull.
Here’s how I do it.
Below are images traced from Kellner and Langston (1996), scaled to the same scale (they were nearly identical in length and proportion) then combined to create the restoration (Fig.1).
The skull turns out to be a little taller due to a low rostral crest, with a taller antorbital fenestra. Kellner and Langson (1996) assumed that the dentary continued on to more of a point and that may be so considering the example of Azhdarcho. The details and sutures of the skull are sometimes easy to make out but otherwise the texture of the gnarled bone makes things more difficult.
All the same size? Yes.
And what does that mean? Were all three specimens juveniles of the same age? Or adults of the same age but of a species distinct from Q. northropi? I don’t know.
The dentary tip
I can only wonder what is going on at the tip of this dentary. It was skewed left and right several times, but in lateral view it appears undistorted. Distinct from sharp-jawed and tooth-tipped Eopteranodon and Eoazhdarcho (which are not azhdarchids), this rostral tip Fig. 3) is wider than tall, like a yardstick. It doesn’t appear strong enough to battle prey that fights back, but supports a gentle wading after tiny crustacean lifestyle.
Kellner AWA and Langston W 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from late Cretaceous sediments of Big Bend National Park, Texas. – Journal of Vertebrate Paleontology 16: 222–231.
Lawson DA 1975. Pterosaur from the latest Cretaceous of West Texas: discovery of the largest flying creature. Science 187: 947-948.