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

[Mickey Mortimer <Mickey_Mortimer111@msn.com>]

Dora Smith wrote-

> I actually wonder, given the evidence that the ancestors of modern birds
> diversified genetically in the early Cretaceous at the latest, if their
> nearest common ancestor belonged to group Aves?    My research on
dinosaurs
> finds considerable convergent evolution among coelurosaurian dinosaurs.
I
> am also finding incredible trouble deciding which feathered critters of
the
> Cretaceous were birds.

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.

Mickey Mortimer