RE: Microraptor and Birds

["Nick Gardner" <ratites637@hotmail.com>]

Tim Williams wrote:

> True, Archaeopterygiformes under my definition (all maniraptorans closer to 
> _Archaeopteryx_ than to _Oviraptor_)  would be effectively equivalent to 
> Sereno's (1998) definition of Paraves (all maniraptorans closer to 
> Neornithes than to _Oviraptor_).  This is because most recent analyses 
> generate a _Archaeopteryx_+Neornithes clade that excludes oviraptorids.  My 
> Archaeopterygiformes is a junior synonym of Paraves as long as maniraptoran 
> phylogeny remains stable in this respect.

I think it might be better to define it as:

Clade Archaeopterygiformes (all maniraptorans closer to _Archaeopteryx_ than 
to _Oviraptor_ or Neornithes)

This way, you still maintain the basic content of _Archaeopteryx_ and not 
the neornithines and this should be favorable in most current and future 
phylogenies, unless we ultimately find that in some most unlikely way that 
Sauriurae is actually a real clade, but the odds are against that happening, 
maybe we should add _Confuciusornis_ and _Enantiornis_ as more taxa that 
Archaeopterygiformes should exclude in its definition (Archaeopteryx <-- 
Oviraptor, Neornithes, Confuciusornis, and Enantiornis).

> Under current phylogenies, this would be the 
> Oviraptorosauria+Therizinosauroidea clade which, as Darren pointed out, is 
> in desperate need of a name.  It is guaranteed to include _Caenagnathus_ 
> (=_Chirostenotes_), especially if _Caenagnathus_ is substituted for 
> _Oviraptor_ in the above definition.

Why does it need a name?  I think it would for now, be better off as a 
stem-based clade, that way we don't have to rename the stem if more basal 
members or sistergroups that were not previously expected were found.  Is it 
possible to define Enigmosauria as the clade containing _Oviraptor_, 
_Caudipteryx_, and _Therizinosaurus_, but not neornithines, deinonychosaurs, 
troodontids, etc.?




nick gardner
 = paleoartist
 = paleogeek

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