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RE: Avian Monophyly (Was Re: Sheesh)... :-)
Evelyn Sobielski wrote:
To which might be replied that Neornithes is monophyletic by definition,
but ratite phylogeny is
still too badly understood to say exactly how deep the paleognath-neognath
I may have my wires crossed here, but I was making the point that the only
birds (avians) *known* to have survived the end-K extinction belong to the
Neornithes. This is true irrespective of how deep the palaeognath-neognath
Supposing the paleognath-neognath split goes back to c. 100 mya (or even
deeper?), then Neornithes becomes a rather arbitrary assemblage united more
by C-T survivorship than by a
robust cladistic model.
If Neornithes is monophyletic (and, as you say, it must be) then it cannot
be an "arbitrary assemblage". I'm confused here.
What they apparently did was to outcompete the transitional paravian flyers
in the Early Cretaceous (although the Enantiornithes certainly had a larger
share in that),
I don't think we have enough evidence for such a detailed scenario regarding
Enantiornithes vs Euornithes. AFAIK, neornithean birds do not appear in the
fossil record until the Late Cretaceous.
4-winged Microraptor had no problem competing with the advanced "true"
avian flyers it appears.
I don't think microraptorans actually competed with birds, any more than
flying squirrels compete with bats nowadays. In this context, 'coexisting'
is probably a better term than 'competing'.
And Archie wouldn't have needed to perch: it had hands. Not fully
functional, but still hands
with discrete fingers.
I tend to agree. Ditto for microraptorans, and probably
(as-yet-undiscovered) basal paravians.
Even pygostyles now appear not to be synapomorphic (i.e. evolving only
There is some question over whether the stumpy coossified tail of certain
oviraptoriforms (_Nomingia_, _Beipiaosaurus_) should actually be termed a
The main problem with that would be competition. It was not the best of
What would _Archaeopteryx_ be running from? It lived on a bunch of islands.
In any case, its cursorial adaptations were about on par with dromaeosaurs
or basal coelurosaurs.
I like a scenario as outlined by Elzanowski in "Mesozoic Birds": Archie
using its wings to gain successively higher perches,
Doesn't this require perching ability?
Use your PC to make calls at very low rates