Chaoyangopterus zhangi (Wang and Zhou 2003), IVPP V 13397, Early Cretaceous, ~140mya, ~26 cm skull length, was originally considerd a nyctosaurid, then a tapejarid (Unwin 2006), then a basal azhdarchoid (Lü and Ji 2006) and finally a pteranodontid (Wang and Zhou 2006). It is easy to see how difficult the problem is because several taxa converge on several characters. Here Chaoyangopterus was derived from the basal azhdarchid Jidapterus and phylogenetically preceded Zhenjiangopterus and Quetzalcoatlus.
Distinct from Jidapterus, the skull of Chaoyangopterus was slightly shorter in length. The jugal was deep, which reduced the size of the orbit.
The sternal complex was wider posteriorly. The scapula, coracoid and humerus were all shorter. The wing, when folded, reached only the base of the neck due to reduced distal phalanges.
The metatarsus ws longer.
See the pterosaur family tree here.