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RE: Gauthier and de Queiroz's Classification of Birds



On Wed, 13 Feb 2002, Williams, Tim wrote:

> > > _Carinatae_ = Clade("keeled sternum" in _Vultur gryphus_)
> > >[snip] And  Confuciusornis and Ingenia with their slight ridge, is that a
> >keel?
>
> And what do you do with _Archaeopteryx bavarica_ which (unlike _A.
> lithographica_) has been described as having a small keel?

"The sternal keel is here defined as a bony crest extendinf from the
ventral midline of the sternum (e.g., _Concornis lacustris_; see
"Comments" below) for an hypertrophied pectoral (flight) musculature (= m.
pectoralis and m. supracoracoideus in the crown; Baumel and Witmer 1993).
REFERRED TAXA: In addition to _Aves_ (see below), _Carinatae_ is currently
thought to include _Ichthyornis_, _Apsaravis_ and _Enantiornithes_ ...
_Confuciusornis_ is the closest known outgroup to _Carinatae_, although it
is polymorphic for the most primitive stage in the evolutionary
development of a sternal keel (Chiappe et al. 1999)."

There's a lot more discussion on this.

In answer to one of Mickey's questions:

"Note that although pterosaur sterna are also keeled, that keel is not
homologous to the keel of _Aves_, and therefore pterosaurs are not part of
_Carinatae_."

On other note: in this paper, _Carinatae_ is considered to include
_Ornithurae_, contra other usages.

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