Re: New alvarezsaurid

["Jaime Headden" <jaemei@hotmail.com>]

<it....>


The kiwi

<...still has the paleognathus palate and other ratite characteristics 
in the hyoid, inner ear, etc. It still has all of the derived 
characteristics of its ancestors, it did not lose two dozen some 
features. Oviraptors and alvarezsaurs do not share any major 
characters.>

No, they don't. They do share closer osteology than alvarezsaurids do to 
various other theropod groups, with the exception of the dromies' and 
Archie's group.

<There are major instances of convergence in Aves, such as the 
repeated developement of the zygodactylus foot, but these features do 
not mean relateness. I think that the two major schemes of bird 
evolution ( Martin : Sauriurae, Ornithurae . And Chiappe: 
Ornithothoraces) still provide better examples of how birds evolved. 
Using both schemes you can tell what is a convergence or what is not. 
Relationships cannot be derived from one or two ambiguous characters, 
but in basic osteology, myology, life histories, behaviors, and DNA.>

Only the first (osteology) can be usefully diagnosed unless we do find 
DNA for a dino (and that depends upon _which_ dino, for it is hardly 
conclusive except for the are-birds-dinos? thing if we get it from a 
hypsie or the like).

Now, how did one bird develop the streptostylic quadrate or tripalatine? 
They just didn't appear in one dino, and you've got a bird, or the 
bird's got it and then the theropod derivative looses the darned thing. 
The fact is, Aves converges greatly within its own groupings to make 
them barely distinguishable from one another except by very distinct 
features (beaks, ornamentation, even ratios [dare say] are not 
conclusive enough). But your point is a valid one---the one theory most 
favorable to osteology is BAMM, BADD is generalistic with its gradual 
progression towards avian characters, and BCF has got the most promising 
future as a debate structure, for its path will be a tortured one (and 
has been) with its mix-and-match avian/theropod characters while birds 
flap about sauropod heads. I propose none of these for myself.

But, we need to start getting back to the original thread: *Shuvuuia's* 
prokinetic jaw (if that's what it is) is either convergent with birds or 
are birds (either solution is equivocal, so to save breath {and numbed 
fingers typing} I need to wait till I get the *Shuvuuia* article in my 
hands or someone can post the data on the skull...

PLEEEEASE!! :-)

I should have done this to begin with. But, if you want to respond to 
this bit, I will continue until I've starved all my little gray cells to 
a neuronic mess.

Jaime A. Headden
Qilongia

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