In our own timeline, there are clear differences between birds and everything else. Birds have feathers, toothless beaks, short tails, and so on… just like mammals have fur and produce milk. In Spec, however, the matter is somewhat more complex. If, on the other hand, lumping tiny tangerines with enormous therizinosaurs seems too ridiculous, then perhaps one could suggest that only those dinosaurs with unambiguous wings, means, with reduced 3rd fingers be called birds? But then our definition excludes bunglebirds, which look far more birdlike than draks? The problem refuses to clarify.