In the history of humanity, there have been a lot of differences in how we looked. The Ducks should have made an evolutionary journey as well. I have made this time line (not very good quality ). I would like to hear your thoughts!
Interesting. I'm not too knowledgeable when it comes to the evolution of birds, but I think the first one (the bird in the nest) should be removed. Anthropomorphic ducks (like Donald) and real birds (like the one in the picture) most likely share a common ancestor, similar to the relationship between humans and chimpanzees. Humans didn't evolve from chimps; they're our "cousins". The same is likely true for Donald and that bird. But then again, I don't know how the evolutionary history of birds work.
It's weird to think that every other anthropomorphic species in the Duck-universe (dog, mouse, pig) would have gone through a similar evolution, parallel to the "cave-ducks". For some reason I think a "cave-pig" would look interesting.
edit: Wait, I just noticed that the little brown bird-baby in image #2 actually appears to be some sort of dinosaur, what with the tail and such. Birds evolved from dinosaurs, I know that much. So yeah, that first bird in the nest in image #1 should be some sort of cousin to the anthropomorphic ducks.
In the story with the bird, the triplets and Gyro go to the past, but to far. However, Gyro says they are still on the timeline of the ducks family tree. The triplets say "Look! This must be family!"
I stumbled over this image (from S 75104) on INDUCKS and was reminded of this thread.
In the original English, the even earlier ancestor in this story is "Duckkus Giganticus," while the bunch pictured in this timeline are "Stupous Duck," "Neanderthal Duck," "Cro-Magnon Duck" and "Modern Duck." Wow, they really strained their brains on the last three. </sarcasm>
In the 2nd guide of Duckburg, hosted by Ludwig von Drake, he listed the 5 most beautiful museum of Duckburg in his opinion. The fifth is the Museo di Scienze Papere (="Museum of Duck Science"). It says: "An interesting didactic itinerary to rethread the evolution of the specie, from the Paperus Erectus to the Paperus Sapiens Sapiens."