Why do you think so? I forget the proper terms, but IIRC the bird wing and bat wing are formed from the basic five-finger plan, but with different bones elongated. Hence, not a transition. They would be able to tell that the bat was a mammal because of its teeth, earbones, single lower jaw, etc etc. It has never, as far as I know, been speculated that pterosaurs are ancestors of birds, even though it seems reasonable at first glance.
I think it's worse than that. The bird wing is the whole arm, but the bat wing is little more than the hand. That pterosaur wing had an incredibly elongated pinkie supporting much of the wing area. The word you probably want is homology, and it isn't there for the bird, bat, and pterosaur wings. They're all independent, as were insect wings.