Re: Outcast Pterosaurs

["Jaime A. Headden" <qilongia@yahoo.com>]

Larry febo wrote:

<OK, ...fair enough. You meant we of the "Orthodox" view, (or BAMM).>

  I am not of the orthodoxy, nor do I subscribe to either BCF, BAMM,
BIFF, or BANG. I take what appears to be the more likely of the given
theories, and formulate my own position. If you need a lable for my
position, I'm floating between BCF and BAMM, and am perfectly
comfortable there.

<I`m not sure how that can be determined from the limited fossil
evidence. I`m assuming that the skin as well as any integumentary
covering would in fact be quite similar. Even the orthodox phylogeny
has pterosaurs as a full blown archosaur.>

  And of that I have no doubt. Of course, Peters gives a good account
of a non-archosaur origin of the pterosaurs, but he does not well
address the position of *Scleromochlus* and lagosuchids (and
*Lewisuchus*) in their similarity to dinosaurs.

<But heck, even Chickens have a rudimentary wing membrane. I notice
this every time I cook one.>

  The patagial structure of arm, pterosaur, and bat wings are all very
different in detail, as James Cunningham notes.

<Padian`s ( and I assume the orthodox) view has it that both
Pterosaurs and Birds developed from cursorial theropod ancestors. In
this case, I believe he is arguing for the homology of the
bird-pterosaur ankle. He points out Lagosuchus (with it`s advanced
mesotarsal ankle) as a possible pterosaur ancestor.>

  Romer and Sereno both argue for a close relationship of lagosuchids
to dinosaurs, and lagosuchids certainly seem to be closer to dinosaurs
than to pterosaurs. They do, infact, form a clade, the Dinosaurimorpha
and Dinosauriformes.

  If it is any known taxon, *Scleromochlus* appears to be the closest
to the common ancestor of both groups, and that is based on an
impression, not the full skeleton.

==
- Greek proverb: "Knowledge is Inherent;
  Stupidity is Learned." -

Jaime A. Headden

Qilong, the website, at:
( http://members.tripod.com/~Qilong/ )
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