Re: "Dinosaurs Died Within Hours After Asteroid Hit Earth..."

[Dora Smith <villandra@austin.rr.com>]

Oh.  So if the most recent common ancestor was at the root of the theropod
line, then all therapods would belong to Aves.

Yours,
Dora Smith
Austin, Texas
villandra@austin.rr.com
----- Original Message -----
From: "T. Michael Keesey" <mightyodinn@yahoo.com>
To: "Mailing List - Dinosaur" <dinosaur@usc.edu>
Cc: "Dora Smith" <villandra@austin.rr.com>
Sent: Saturday, May 29, 2004 10:18 AM
Subject: Re: "Dinosaurs Died Within Hours After Asteroid Hit Earth..."


> --- Dora Smith <villandra@austin.rr.com> wrote:
> > By what definition of Aves?   If Bird can be defined any way one wants
and
> > Microraptor, which was a member of another line of dinosaurs, qualifies
as
> > much as a bird as archaeopteryx does, then is "Aves" anything with
feathers?
> > If so, then any coelorusaurian dinosaur would qualify as a member of
Aves.
>
> _Aves_ and "birds" are not necessarily the same thing. Here are the
definitions
> (and I don't have my refs with me, so if anybody sees errors, please
correct
> them):
>
> _Aves_ Linnaeus 1758 sensu Gauthier 1986 (made explicit in de Queiroz &
> Gauthier 2002):
> The most recent common ancestor of _Struthio camelus_ (ostrich), _Tetrao
> [Tinamus] major_ (great tinamou), and _Vultur gryphus_ (Andean condor),
plus
> all of that ancestor's descendants.
>
> _Aves_ sensu Chiappe 1992:
> The most recent common ancestor of _Archaeopteryx_ and modern birds, plus
all
> of that ancestor's descendants.
>
> _Neornithes_ Gadow 1893 sensu ???:
> same as _Aves_ sensu Gauthier 1986 (But has this actually been
phylogenetically
> defined in some paper? I'm not sure.)
>
> _Avialae_ Gauthier 1986:
> The first ancestor of modern birds (_Aves_ sensu Gauthier 1986) which is
not
> also ancestral to _Deinonychus_, plus all of that ancestor's descendants.
>
> _Avialae_ sensu Wagner and Gauthier 1999:
> Same as _Aves_ sensu Chiappe
>
> _Avialae_ sensu de Queiroz and Gauthier 2002:
> The first ancestor of _Vultur gryphus_ to have powered flight homologous
with
> that in _V. gryphus_, plus all of that ancestor's descendants.
>
> _Avifilopluma_ de Queiroz and Gauthier 2002:
> The first ancestor of _Vultur gryphus_ to have feathers (hollow-based,
> filamentous, epidermal appendages produced by follicles) homologous with
those
> in _V. gryphus_, plus all of that ancestor's descendants.
>
> _Aviplumosa_ de Queiroz and Gauthier 2002:
> The first ancestor of _Vultur gryphus_ to have "natal" down homologous
with
> that in _V. gryphus_, plus all of that ancestor's descendants.
>
> _Avipinna_ de Queiroz and Gauthier 2002:
> The first ancestor of _Vultur gryphus_ to have pennaceous feathers
homologous
> with those in _V. gryphus_, plus all of that ancestor's descendants.
>
> _Aviremigia_ de Queiroz and Gauthier 2002:
> The first ancestor of _Vultur gryphus_ to have remiges and rectrices
homologous
> with those in _V. gryphus_, plus all of that ancestor's descendants.
>
> "bird":
> An English vernacular term that has a pretty clear application insofar as
> extant  animals are concerned (modern avians or avialans sensu anybody),
but is
> rather fuzzy when applied to extinct forms. Various authors more or less
equate
> "bird" with any of the clades mentioned above, although most commonly with
> _Aves_ sensu Chiappe or _Avialae_ sensu Gauthier 1986.
>
> To make sense of the above definitions, here is a cladogram showing the
> specifier taxa and apomorphies in their most commonly accepted pattern
(this
> requires a monospaced font):
>
> --+--(feathers sensu de Queiroz and Gauthier 2002)
>   `--+--("natal" down)
>      `--+--(pennaceous feathers)
>         `--+--(remiges and rectrices)
>            `--+--_Deinonychus_
>               `--+?-(powered flight [possibly earlier or later?])
>                  `--+--_Archaeopteryx_
>                     `--"modern birds"
>                        |--_Vultur gryphus_
>                        `--+--_Struthio camelus_
>                           `--_Tinamus major_
>
> As I've said before on the list, I feel that the term "bird" should
generally
> be avoided in technical discussions. Use whichever of the above clades you
> mean.
>
> > What I am wondering is if birds really did come from just one narrow
line of
> > coelorusaurs.
>
> You'd have to clarify what you mean by "bird".
>
>
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