Preondactylus bufarinii (Wild 1983) Norian, Late Triassic, ~205 mya was considered by Unwin (2003) to be the most basal pterosaur. It is not. Derived from a sister to the Italian specimen of Austriadactylus, Preondactylus phylogenetically preceded Dimorphodon.
Distinct from Austriadactylus, the skull of Preondactylus was lower and narrower with a larger antorbital fenestra completely posterior to the naris.
The cervicals were shorter, the caudals more robust.
The scapula and coracoid were more robust and straighter. The sternum was much larger. The humerus was anteriorly concave. The ulna and radius were shorter. The pelvis and pes were relatively longer. Pedal digit IV was shorter and V was longer. The metatarsals were longer than the pedal digits and IV was shorter than III.