Actually there are several flying dinos resembling wyverns. The Dimorphodon is which I usually think the most fitting, but the Rhamphorhynchus also looks very much like a rather slender wyvern. In relatively small sizes the construction is perfectly viable and proven, even today one could probably exist, competing with birds, (fruit) bats and flying squirrels for the niche of an efficient arboreal creature relying on both being a good climber and short distance flyer.

Flying is tricky though, especially for larger beasts. They need soaring to be efficient, and that kind of flight has a lot of constraints, most notably for the center of mass and the shape of the wings. The big pterosaurs looked the way they did for this reason. I think the most accurate site on the matter is this, but pterosaur.net also feels like a good source (the two contradict each other in some subjects).

I am experimenting with constructs which look wyvern, are large, and might be airworthy (or at least a lot nearer to it than common dragon or wyvern depictions). What can not be eliminated is a thin hindpart compared to the front to balance them well for flight, and for truly efficient soarers a fitting wing shape. The large wyvern if it could reasonably exist would evolve based on a mixed ground and air preference. An interesting advantage to birds if their anatomy fits (pterosaur.net describes this at Flight) is that they could perform a quadrupedal launch, using their powerful forelimbs as well for kicking themselves in the air.

(There is an other potentially possible contraption for a four limbed dragon which you will find in my gallery: those once evolved would be very capable flyers, but the existence of an evolution path leading there is quite dubious)

Anyway, interesting stuff to go around researching these!