[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Gauthier and de Queiroz's Classification of Birds

On Tue, 12 Feb 2002, Williams, Tim 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'm still formulating them. :)

It's interesting that, while they specifically (and validly, IMHO) list
the reasons why _Ornithosuchia_ should not be used, they dismiss
_Avemetatarsalia_ out of hand, and never mention _Ornithotarsi_.

> I remember scratching my head at some of Gauthier and de Queiroz's
> definitions;

Yes -- _Avifilopluma_ seems so vague as to be useless to me. As they note,
it could be anything from a subclade of _Maniraptora_ to a near-synonym of
_Tetanurae_. I'd rather just say "filoplumed theropods" or something
rather than erect a whole taxon for it....

They do this as a way of giving _Aves_ as is it used by some researchers a
new name. (Although I don't really see too many researchers using it that

> 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_.

Excellent point. In fact, they are careful not to assert that
_Archaeopteryx_ was definitely capable of powered flight, so, in essence,
they admit it's a kind of vague definition....

> >_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.

OOOOH, I see... They use this notation:
_Tetrao [Tinamus] major_ Gmelin 1789
To indicate that, although it was originally placed in _Tetrao_, it has
since been moved to _Tinamus_. Ha ha -- I was wondering, "When the heck
did the chicken get placed in _Phasianus_?..."

Good thing they include the species' citations.
 The Dinosauricon        <http://dinosauricon.com>
  BloodySteak             <http://www.bloodysteak.com>
   personal                <keesey@bigfoot.com> --> <tmk@dinosauricon.com>
    Dinosauricon-related    <dinosaur@dinosauricon.com>
     AOL Instant Messenger   <Ric Blayze>
      ICQ                     <77314901>
       Yahoo! Messenger        <Mighty Odinn>