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RE: Air sacs in extant non-avian reptiles?



> From: ELurio@aol.com [mailto:ELurio@aol.com]
>
> << Please ignore the outburst of Eric Lurio, quoted below.  He
> seems to be
> very
>
> emotionally attached to a number of out-moded concepts.
>
>
> In point of fact, the majority of evolutionary biologists working on
>
> vertebrate relationships today (paleontologist and neontologist
> alike) agree
>
> that the evidence for the dinosaurian origin of birds is vastly stronger
>
> than the alternatives.  A small group of physiologists and a couple of
>
> paleontologists reject this idea quite loudly, although not very
>
> effectively.  Lurio seems to have accpeted their arguments hook, line, and
>
> sinker. >>
>
> Have you actually compared a pidgen with a gecko?

Yep.

>The differences are enormous!!!!

Sure are.  Evolution happens.

Did you not happen to catch the line in the posting you quote which read:
"a shift in the convention of naming groups, with a traditional system based
on grades of organization and the current system based on nested pattern of
ancestry."

When you come to understand the change in this shift, you'll figure this
out.

> The small group of physiologists  n fact accounts for
> practically all of them working today, not to mention every single
> orthinologists.

Ummmm, no.  As I said before, Lurio has fallen for the PR of the
anti-dinosaur origin of birds crowd hook, line, and sinker.

Altogether there are only a relatively small number of physiologists working
on questions pertinent to the evolution of amniotes.  Ruben and his students
do represent a good chunk of them, sure.  However, Colleen Farmer (Univ.
California Irvine) and David Carrier (Univ. Utah) must also be counted among
them, and they accept the morphological evidence for the dinosaurian origin
of birds, as does Robert Dudley (Univ. Texas Austin), who recently reviewed
flight origin issues in Annual Review of Physiology.

Eric, can you please cite some currently active physiologists other than the
members of the Ruben team who have published that they reject the
dinosaurian origin of birds?

As for ornithologists:  yes, two prominent workers on Tertiary birds
(Feduccia and Olson) reject the dinosaurian origin of birds.  Chiappe (a
Mesozoic bird expert) and Gareth Dyke and other paleornithologists accept
the evidence.  Some neo-ornithologists (e.g. David Mindell) are playing it
safe, saying that the origin of birds is in debate but not rejecting one or
the other hypothesis just yet.

Eric, can you provide some citations from current books on ornithology other
than those by Feduccia and Olson which outright reject the dinosaurian
origin of birds?

>Birds are as much reptiles as they are fish.

NOW you're beginning to get the hang of it :-]

(Although "fish" is a grade of organization.  However, I would agree that
Aves is as much a part of Reptilia as it is part of Osteichtyes (or
Gnathostomata or Deuterostomia)).

>The convention of naming groups is a highly political activity, and the
>change of the term "reptile" is an example of this. The preferred term is
>"amniote." A chicken is as much of a reptile as you are.

Nope.  Amniota is a different clade: it encompasses not only reptiles, but
mammals and their extinct relatives as well.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-314-7843