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Re: Giant birds



Jaime A. Headden wrote:

>I think there's overwhelming evidence for dromies
>as the sister taxa to birds, then, successively,
>oviraptors, troodontids, ornithomimids and
>tyrannosaurs, coelurids, and compsognathids, withing
>coelurosaurs. [By "coelurids", I include *Coelurus*,
>*Ornitholestes*, *Nedcolbertia* et al. within a
>monophyletic group, but could be wrong].

So this means that the clade for the first three would look like this:

+--------------Troodontids
|
|  +-----------Oviraptors
|__|
   |     +-----Deinonychosaurs
   +-----|
         +-----Avialae

I'm surprised at this. I would expect that troodontids + deinonychosaurs
would be the sister group to Avialae, and then oviraptors and ornithomimids
would be successive sister groups to the crown clade (based strictly on
what I've read, not on first-hand information). Doesn't the enlarged second
toe unite them to the exclusion of birds? BTW, which is more acceptable,
dromaeosaur or deinonychosaurs?

Raymond Thaddeus C. Ancog
Mines and Geosciences Bureau
Philippines