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RE: Megalancosaurus, Longisquama & other oddballs



> -----Original Message-----
> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Ken Kinman
> Sent: Friday, March 16, 2001 5:19 PM
> To: dinosaur@usc.edu
> Subject: Megalancosaurus, Longisquama & other oddballs
>
>
> Renesto and Tom,
>       I am certainly looking forward to Merck's phylogenetic
> analysis (will
> it be out by this summer??).

Sad to say, it will not be out during 2001.  (One of his big tasks this
summer is to get a publishable version done).

>       It seems like the whole basal Archosauromorph phylogeny is still a
> huge controversial mess.  Even what to include in
> Prolacertiformes seems far
> from settled.  Whether to include Megalancosaurus or not, and some don't
> even include Protorosaurus any more (so whether Protorosauria and
> Prolacertiformes are synonymous or independent groups is still
> very much up
> in the air).
>       Until there is a more settled phylogeny, it seems like
> speculations on
> the evolution of arboreality, gliding, feathers (or anything else) in
> archosauromorphs cannot be tested very effectively.  Am I being overly
> pessimistic?

Overly pessimistic, yes, in so far as the evolution of arboreality, gliding,
etc. for bats and birds can still be well studied (since these are, based on
all other available evidence, placental mammals and theropod dinosaurs
respectively).  Where the problem does seem to lie is with pterosaurs, as
the evidence does seem to be mounting for a more primitive archosauriform
position for those guys.

However, even there one can still provisionally test some ideas by using a
couple of different alternative scenarios.

                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): 301-405-0796