Why do the Scientists rely on the Artists?

This article about the earliest flying dinosaur is just another example to me that scientist don't have any clue what these ancient creatures used to look like. Here is the Article It seems to me that all scientist do is unearth the bones, look for clues, write down all the info and then hand it to an artist and say "Here, draw us what that looked like." NOBODY KNOWS WHAT THAT LOOKED LIKE!
No one was alive to document how these animals looked or behaved, we can't just figure that out by comparing them to animals that live know and hope that they had the same social behaviors and evolutionary patterns. Artists do there best to recreate these dinosaurs, but saying that you can recreate it well enough to test it in a wind tunnel and figure out the origins of flight? COME ON! I don't think so. Birds fly not just because they have feathers, but because of there structure and there are many feathered creatures that just don't fly, so I'm sorry but I don't believe that you will be finding the origins of flight any time soon, just because you like the way that the artist did the rendering. I'm do think it looks amazing, but that doesn't mean that it was like that or that it flew at all.