Re: [asa] Did dinosaurs become chickens?

But the real proof in the pudding is that just about every kind of meat
except beef "tastes like chicken."

On Fri, Jan 30, 2009 at 11:41 AM, <kbmill@ksu.edu> wrote:

>
> > A naive question. How can dinosaurs evolve into chickens if the
> > extinction of dinosaurs occurred suddenly?
>
> Two different questions, I will respond to the one above first.
> Taxonomy is the procedure for assigning names to species and to groups
> of species. The field of systematics involves developing the criteria
> by which organisms are grouped into a heirarchy of categories. There
> are different competing methodologies for how this is done. The most
> influential systematics being used today is cladistics. Using
> cladistic proceedures, birds (all birds) are a subset of the dinosaur
> group. In this classification, birds ARE dinosaurs. Therefore,
> dinosaurs as a group did not go extinct at the end of the Cretaceous.
> However, if you used the older "evolutionary" classification system or
> the still older Linnean classification system , birds were grouped as a
> separate class. Using that classification, dinosaurs did go extinct.
> It is important to understand that classifying birds in a separate
> group does not imply that they are unrelated to dinosaurs.
>
> In response to the question in your subject line: The fossil evidence
> for the evolution of birds from the maniraptoran group of dinosaurs
> (Oviraptors, Troodontids, Therizinosaurs, Dromaeosaurids) is very
> extensive and rapidly increasing. There are now numerous dinosaur
> specimens that show transitional characters with the earliest birds.
> Various maniraptoran dinosaurs (especially the Dromaeosaurids)exhibit
> nearly all of the diagnostic skeletal features of the earliest
> unquestioned birds. As with other cases in which there is a good
> fossil record, there are specimens whose proper classification is in
> question. Paleontologists talk of avian and non-avian dinosaurs - the
> the distinctions are sometimes very subtle and disputed. The origin of
> birds from maniraptoran dinosaurs has been given increased support with
> the discovery of non-avian dinosaurs with various filamentous and
> feather-like body coverings. Some even have true feathers, and a few
> (eg Microraptor) may have been capable of gliding flight.
>
> I discuss some of this in my book chapter on transitional forms in
> "Perspectives on an Evolving Creation." However, even since the
> publication of that book in 2004, there have been many new fossil
> discoveries that have further filled in and illuminated the
> maniraptoran - bird transition.
>
> Keith
>
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Received on Fri Jan 30 11:46:31 2009