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Re: bauplan convergence

From: "Ahmed al-Mahasa Sha'ad"
Are you serious?? You must know about the 'fuzzy' theropods like
Sinornithisaurus, Bepaisoaurus, Sinosauropteryx which  show a cobvering of
hair-like structures. Feathers evolved from this- true feathers I mean like
you see  in Caudipteryx and birds.

Yes, these theropods have some form of furry proto-feathers. However, these animals are coming from the late Jurassic and early Cretaceous, and not from the time before Archaeopteryx. Yes, this tells us that these dinosaurs had proto-feathers, and further study of these animals points towards a common ancestor. So, does this common ancestor have some form of primitive feathers/flaps/skin anamolies that could have led to feathers/proto-feathers. We know (From Archaeopteryx) that some dinosaurs had full-fledged feathers by the middle Jurassic. So, are these late Jurassic/Early Cretaceous theropods abrerations, dinosaur lineages that never developed flight, or descendants of animals that had once developed flight and then lost it in favor of (fill in blank).
So, while these finds are quite fascinating, since they occur *after* the origin of avian flight, they only lend a hint at how avian flight developed. Until we find a pre-Archeopteryx dinosaur *with* some form of proto feathers, this all remains speculation, based on extrapolation.

Who cares???   Did you read my last messsage>?    It is not compulsary for
ALL lineages to copy each other!@!!Why did creodonts return to the sea and
evolve into whales, but why not dogs? They are both terestriall carnivores?

The question isn't why hasn't it evolved in other animals, rather, why did it develop in dinosaurs in the first place. I guess it was kind of redundant for me to ask that, when that was the subject being discussed in the first place.


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