RE: Gauthier and de Queiroz's Classification of Birds

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

T. Mike Keesey wrote:

>I'm still formulating opinions, myself. There is a big emphasis on crown
>clades and apomorphy-based clades, and every single stem-based clade
>starts with "Pan-". 

Sounds like Pan-demonium. :-)  My head started spinning while reading this
chapter, so the opinions I formulated may be different from Mike's.  I
remember scratching my head at some of Gauthier and de Queiroz's
definitions; I'm not crazy about apomorphy-based definitions, but I'm
especially leery of those that invoke a specific function as part of the
definition ("feathered wings used for powered flight").  _Archaeopteryx_ is
widely (but not universally) regarded as having achieved powered flight,
though lying not too far from the threshold.  However, no one has observed
_Archaeopteryx_ in flight, and this definition could become very contentious
should somebody find a feathered "dino-bird" slightly more primitive than
_Archaeopteryx_.  

>_Aves_ = Clade(_Struthio camelus_ + _Tetrao [Tinamus] major_ + _Vultur
>gryphus_)

_Tetrao_ is the generic name for grouse (Tetraonidae, Galliformes).  AFAIK,
_Tinamus major_ (type of _Tinamus_; formerly _Tetrao major_) is the correct
name for the Great tinamou.



Tim


------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163