Well, maybe, maybe not… but let’s explore the concept. I’ve animated the possibility (Figs. 1, 2). Let’s look for problems.
Perhaps all pterosaurs were able to hover only briefly, especially at take-off and landing. A vertical take-off would have facilitated lift-off from water, if floating prior to flying.
Hovering would also have facilitated accurate landings on small runways, like branches, by rapidly reducing forward airspeed by “raising the nose,” presenting the maximum area for drag and rotating the thrust component downward.
Rotation to the minimum drag flight configuration
From the hovering mode, simply dropping or extending the skull anteriorly, especially in long-necked forms, would have rotated the pterosaur to the traditional flight configuration, reducing drag to a minimum and rotating the thrust vector to the horizontal to maximize airspeed.
Tiny vs. giant
Perhaps certain tiny pterosaurs with a large sternal complex, like BMNH 42736, would have found hovering easier due to their tiny size. We can only image a giant pterosaur hovering at present. Perhaps it is unlikely or impossible, as in large birds.
The ability to hover must be considered the acme of flight in vertebrates, requiring the most sensitive and energetic sort of morphology and metabolism. We know that pterosaur wings were imbued with nerves and blood vessels, so there would have been a constant stream of instructions and feedback traveling back and forth to the brain.
Sternal complex variations
The sternum in birds differs greatly, from the giant sternum in hummingbirds, to the much smaller one in ostriches. Similarly, in pterosaurs the sternal complex varies greatly, from the giant broad one in Dendrorhynchoides to the rather tiny ones in Dorygnathus. This may have something to do with hovering and vertical take-off. Not sure. Makes sense.
This hypothesis and model is shown with the narrow-chord wing membrane found in all known pterosaurs that preserve the wing membrane. A narrower wing membrane can flap more quickly due to less drag.
I really don’t see any problems having tiny pterosaurs hover — especially during take-off and landing — and thus for only short periods of time. Perhaps the best of them had the deepest or largest sternal complex. Perhaps these could hover for longer periods of time.
Notably, the vampire pterosaur, Jeholopterus, had a very small sternal complex. So, given this hypothesis, it is unlikely that it hovered the way Dendrorhynchoides and other anurognathids could have. Instead, Jeholopterus more likely landed with a thud.
As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.
Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.