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Re: A Word on ABSRD



Sorry to answer so late...

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>
To: <dinosaur@usc.edu>
Cc: <kinman@hotmail.com>
Sent: Thursday, February 15, 2001 6:54 AM
Subject: Re: A Word on ABSRD


> Ken Kinman (kinman@hotmail.com) wrote:
>
> <I have expressed my hopes that the "Birds Came First" Theory is
> actually true, because it could very well turn out that "birds"
> (not Aves) did evolve from very primitive dinosaurs or even
> dinosauriforms,>
>
>   This is not BCF, this is Chatterjee's perspective. BCF holds
> that so-called avian morphology was kickstarted in the Triassic
> and that dinosaurs have become explicitly terrestrial from an
> arboreal ancestor, to which they _returned_ in the maniraptoran
> fold, then "true" birds.

Chatterjee, however, thinks that birds and dromaeosaurs are sister groups,
that their common ancestor was scansorial (and that later dromaeosaurs may
have attacked from above), that ornithomimosaurs were arboreal herbivores
(!!!), and so on. He often says that *Protoavis* (oh, it's mantra time: next
part of Details On forthcoming...) does nothing to the topology of the
existing cladograms, it just pulls lots of branching events into the LT.

BANDits say that *P.* is too old to have dinosaurian ancestors; Chatterjee
apparently disagrees.

> <Whether we then expand Aves to include maniraptors is a bridge
> we will have to cross if and when we get there.>
>
>   "Aves" has been classically used to include *Archaeopteryx*
> since the 1860's. Gauthier explicitly stated this, and Chiappe
> refined it by framing the statement in phylogenentic terms.

Speculative scenario (shameless self-promotion strikes again)... what if,
say, my phylogeny, (Compsognathidae + (*Archaeopteryx* ?+ *Rahonavis* +
Dromaeosauridae) + (Arctometatarsalia + (Oviraptorosauria + (Alvarezsauridae
+ *Yandangornis* + *Avimimus* + Pygostylia)))), comes to be accepted :-]
_before Aves will have been given a definition under the PhyloCode_? Then,
as long as people don't use the crown-group definition of Aves (hardly
anyone still does), *Utahraptor*, *Tyrannosaurus* and *Ornithomimus* are
members of Aves (*Archaeopteryx* + Neornithes). While there are people who
have expressed views like "then so be it", how many people would think so,
too, rather than change the definition of Aves? (Qualifying clauses?)