Re: New alvarezsaurid

["Matthew Troutman" <m_troutman@hotmail.com>]

>
>I'm not dismissing these characters. Only saying they point to a more 
>derived state that the oviraptorosaurs, which can be said of all birds 
>as opposed to, say, dromaeosaurs, which I actually do believe are 
>antecendant to modern birds. Just that the alvarezsaurids are not 
>derived from the modern avian lingeage, but I side-course.

     I think that though they are not related to the true ancestors of 
modern birds directly, they are derived from Archaeopteryx-like ancestor 
and have no relationship with oviraptorosaurs.


>
>>1) They lack many avian features that even dromaeosaurs have.
>>2) Dromaeosaurs share a common ancestor with the stock that >>spawned 
>>Archaeopteryx.>
>
>And both *Archeopteryx* and *Dromaeosaurus* shared a common ancestor 
>with *Oviraptor,* which was my point. I'm saying that if dromies 
dropped 
>characters that Archie derived from primitive stock (dromies my have 
>retained the primitive condition, while Archie derived them from their 
>MRCA; or dromies dropped the refined characters that Archie retained, 
>again from that MRCA) then those primitive characters would be used as 
>*Oviraptor's* starting point, as well as *Shuvuuia*.

    Oviraptorosaurs are not directly related to dromaeosaurs and 
Archaeopteryx. They lack all of the characters that link the two groups 
and all that define birds. 

>This could also mean *Shuuvia* retained the characters, which Ovi's 
line 
>dropped, thus seeming more primitive.

    There is no evidence that oviraptorosaurs dropped these characters. 
We do have evidence that they probably never had them. Oviraptorosaurs 
and alvarezsaurs share no main characteristics.


>unnamed node (in my case, or I don't know what it is)
> \_
>  |\_Paraves
>  |  |
>  |  \__Archaeopterygidae
>  |   | \_Aves
>  |   |
>  |   \_*Dromaeosauridae
>  |
>  \_unnamed node (in may case)
>    |
>    \_Alvarezsauria
>     \_*Oviraptorosauria
>
>Here, the derived groups (*) are actually the less bird-like 
>(comparatively) than the primitive groups, which are very bird like, 
and 
>Aves would have actually sprang from the primitive form, suggesting 
that 
>our famous raptors, "the ancestors of birds", where not so, but were 
>advanced protobirds, while birds are actually primitive. From such a 
>theme, alvarezsaurids and my oviraptorosauria inclusion would be as 
such 
>suggested. This would also help with the present fossil evidence and 
>relative ages for all groups.

     I don't understand still. All I see between oviraptorosaurs and 
alvarezsaurs is a convergent shoulder structure and that's it. There is 
no reason to suspect that they have derived from oviraptorosaurs. Still 
the supposed primitive group does not have all the features that 
alvarezsaurs shared with birds ( double-headed qudrate, lack of 
ascending process of the jugal, etc.).

>unnamed node (in my case, or I don't know what it is)
> \_
>  |\_Paraves
>  |  |   
>  |  \_*Dromaeosauridae
>  |    \_Archaeopterygidae
>  |      \_Aves
>  |
>  \_unnamed node (in may case)
>    |
>    \_*Oviraptorosauria
>     \_Alvarezsauria
>
>This would be the cursorial-to-volant form, with each group leading to 
a 
>more "advanced" flying mode, but Archie came before dromies, so this is 
>doubtful. Oviraptorosaurs and alvarezsaurids fit in like they did in 
the 
>previous clade, but with less bird-like ovis as preceding the cursorial 
>alvarezsaurids, which would actually agree itself with the fossil 
>record, rather than the previous clade.

     This starts up even more convergence.

>Maniraptoriformes
> \_Maniraptora
> | \_Paraves
> |  |\__Archaeopterygidae
> |  | | \_Aves
> |  | \_*Dromaeosauridae
> |  \_Alvarezsauria
> |
> \_*Oviraptorosauria
>
>This would also agree with the fossil record, and is the presently 
>assumed association. This has as much merit as my association, perhaps 
>more, but mine simply assumes a closer association of alvarezsaurids 
>with ovis than with dromies and Archie. Also, it places ovis outside 
>Maniraptora as based on a few avian characters that Ovi lacks, but my 
>association argues for a loss of characters from a state that possesed 
>so-called "bird" qualities, and thus messed us up.

     This causes more convergence. The idea that dromaeosaurs are 
derived from Archaeopteryx is inheritantly unstable because it would 
cause a lot of convergence.

MattTroutman

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