Re: "Dinosaurs Died Within Hours After Asteroid Hit Earth..."

[Dora Smith <villandra@austin.rr.com>]

"> By definition yes, the most recent common ancestor of modern birds was a
> member of Aves, following any reasonable phylogeny.  This holds for
Gauthier
> and de Queiroz's definition (Struthio maximus + Tinamus major + Vultur
> gryphus) or Chiappe's (Archaeopteryx lithographica + Vultur gryphus).
> "Bird" can be defined basically any way you want.  I equate it with Aves,
> but Microraptor's about as birdy as Archaeopteryx, so including all
> eumaniraptorans doesn't seem too odd."
>

By what definition of Aves?   If Bird can be defined any way one wants and
Microraptor, which was a member of another line of dinosaurs, qualifies as
much as a bird as archaeopteryx does, then is "Aves" anything with feathers?
If so, then any coelorusaurian dinosaur would qualify as a member of Aves.

What I am wondering is if birds really did come from just one narrow line of
coelorusaurs.


My question on birds originating in Antartica or on the southern continent
is were not other dinosaurs also in that place at the time.    If as the
genetic studies suggest the major categories of birds diverged during the
Cretaceous, then atleast four to six groups of birds survived the exinction.
How come they were the only dinosaurs?

Yours,
Dora Smith
Austin, Texas
villandra@austin.rr.com