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Re: back to pteros



David Peters (davidrpeters@earthlink.net) wrote:
<The first ptero egg turned out to be an anurognathid. You're not going to get
additional rostrum shortening in this clade, so it's rostrum is as short as
those of other anurognathids. The second Chinese ptero egg belongs to a
basalmost ornithocheirid still retaining some cycnorhamphid characters (long
legs, for instance).  You can see my take on it at:>

  Unfortunately, the first specimen is an anurognathid only in Dave's eyes.
This is based on a highgly contentious technique which has been substantially
criticized for it'd highly subjective nature. This same technique resulted in
the finding of a skull in a specimen of juvenile *Pterodaustro* which,
according to the people who have studied it first hand, doesn't exist. If when
every bone is present as physcial material, there are hidden impressions that
only Dave Peters has ever reported, it is neccessary to corroborate this data
by independant means. So far all independant observations made on the list or
even in press (Chris Bennett wrote a response in _Prehistoric Times_ to Dave
Peters' *Avgodectes* paper which entirely contradicts his claims). How can we
still say such things as "turned out to be" in any conclusive way with this
amount of contradictory data?

<Note that the rostrum shows no shortening whatsoever.>

  This is irrelevant, actually, as positive allometry of the snout and negative
allometry of the non-snout cranium are typical among vertebrates. But don't
take my word for it, read some BioDev texts. They are repleat with cases of
this and even demonstrate formulaic data in mammals, birds, crocs, and so
forth. All living reptiles, mammals, amphibians, and most if not all fish
exhibit this trend in short-snout/huge-eye/large-head-to-body condition, the
so-called "cuteness", and there is no reason singular observation without
corroboration shoudl upset this _a priori_ data unless better substantiated
than the photointerpretive technique so far undetailedly shown. This is not a
rejection of theory so much as a rejection of the method at which this data is
arrived at. All unproven scientific methods undergo the same procedure, and
it's no reason this is different; this was true for Hoagland's "Face on Mars"
and it continues to be true.

<Your examples of gharials and cranes unfortunately slipped back into
archosaurs, which are born cuter than most, as noted earlier.>

  Again, this statement begs for an objective cuteness scale -- which is, I
beleive, an oxymoron. Furthermore, since this condition appears in fish and
mammals, it is not "back into archosaurs." Using pterosaurs and personal
subjective interpretation of slabs does not change this.

<Chiappe's decision might have been subjective ( personally, I think he
measured everything that could be measured),>

  [including the absence of a skull...]

<It would help, Jaime, if you indicated what sort of lizards  they rather look
like.>

  They resemble, rather subjectively I might add, like adult tuataras. Which,
being embryos, they most certainly are not.

<1. The original Langobardisaurus paper by Silvio Renesto described a complete
skeleton with a skull and cervical series preserved beneath the rib cage. The
reconstruction showed a rather low skull with Macrocnemus proportions. My
tracing of a photo indicated a large, short-snouted, giant orbit (rather
juvenile in all aspects!) skull that subsequently was validated by the third
Langobardisaurus specimen with a skull out in the open.>

  Rather juvenile in the archosaur sense, or rather juvenile in the really
tirangular, *Cosesaurus*/*Megalancosaurus* Avecephala sense? And, have you
accounted for fracturing, distortion in crushing a 3D skull into a flat bone on
deforming dolomitic rock?

<Other observations, such as the posterior of Longisquama, the forelimbs of
Sharovipteryx, the narrow chord wing on Sordes, the palate of Jeholopterus, the
sclerotic ring that turned out to be a premaxilla in Tischlinger's tiny
anurognathus and the like, have yet to be considered by others in print ? one
way or the other. Private requests to demonstrate alternate reconstructions and
phylogenies based on same have all gone unanswered ? but you can't blame them
if there's nothing there!>

  The narrow vs. broad chord wings of *Sordes* have been broadly contended in
print, actually. Dave is simply siding with one position using this technique.
This is not truly to argue over whether it had a narrow vs a broad chord,
especially when one would offer that the skeleton would shift AFTER the skin
had degraded into the fossilized substrate without leaving impressions of the
limbs in their original positions, or that the tissues would become loosened
and move about during this process as if the skin were so easily detachable
during decomp. This is simply illogical. Other ID's have not been substantiated
by any other than the aforementioned contended technique, which has been
objected to in print. This is substantial enough. However, until this "new"
data of Dave's is itself published and if or when the technique is proven,
objections can be raised then. Notice also that Hoagland's far fetched Face on
Mars interpretation  is similarly relegated to internet discussions ... like
this one.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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