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

[Christopher Taylor <ck.taylor@auckland.ac.nz>]

    What is the full reference for this? I wasn't aware that any flying stem
Sphenisciformes had been discovered - or has _Manu_ or some other
procellariiform fossil been reassigned?

    Cheers,

        Christopher Taylor

On 2/6/04 4:01 am, "Tim Williams" <twilliams_alpha@hotmail.com> wrote:

> 
> David Marjanovic wrote:
> 
>> This one... there are only 2 possibilities: either it's a loriid, means, it
>> belongs to a _part_ of the crown group of Psittaciformes, or it's not a
>> psittaciform.
> 
> Correct me if I'm wrong, but I do not believe that modern avian "orders"
> (e.g., Psittaciformes, Galliformes, Sphenisciformes) are restricted by
> definition to their respective crown groups.  Fossil taxa (e.g.,
> Gallinuloididae) have been referred to the Galliformes as stem taxa that do
> not belong to the crown group.  Further, here's what Clarke et al. (2003)
> have to say for the penguin clade:
> 
> " ?Pansphenisciformes? is used here as a name for all taxa more closely
> related to extant penguins than to any other extant avian taxa.
> ?Sphenisciformes? is suggested as a name for all parts of this lineage with
> a loss of aerial flight homologous with that of extant penguins. These
> definitions are deliberately not formalized pending recommendation of the
> PhyloCode regarding the proposed use of ?pan? as a prefix in all stem clade
> names (Gauthier and de Queiroz, 2001 ) and to allow penguin specialists to
> debate appropriate definitions for these names prior to the start date of
> the PhyloCode (Cantino and de Queiroz, 2000 ).  As all extant penguins have
> consistently been placed in the ?family? Spheniscidae, it is also
> recommended that the name ?Spheniscidae? be formally applied to the clade
> comprised of the most recent common ancestor of all extant penguins and all
> of its descendants. "
> 
> Thus, Clarke et al. (2003) propose a stem-based definition for
> Pansphenisciformes, an apomorphy-based definition for Sphenisciformes, and a
> node-based definition for Spheniscidae (= crown group).
> 
> 
> Tim
> 
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