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Re: PROJECTILE URINATION?
Bruce Shillinglaw wrote:
<What is the story with the pterosaurs? I thought that
it had finally been decided that pterosaur wings
attached to the body at the hip, not the ankle! Was I
mistaken? Or are there some new discoveries that I was
not aware of?>
It has never been "decided" that pterosaurs had
brachiopatagia attaching to the hip. Skelopatagia
(brachiopatagia extending to the ankle or shin) are
preserved in numerous fossils of *Rhamphorhynchus* and
*Sordes*; whereas the *Pterodactylus* imprint
specimens appear to have had narrower brachiopatagia,
and may not have articulated to the shin or ankle, but
to the thigh or knee (cruropatagia); suggested has
been a novel patagial structure in some pterosaurs
that lack preserved impressions, but I'll wait for the
paper to come out. Skelo- to cruro- patagial extension
may apply to a functional consideration, but I don't
study these things....
Peters published a paper replied to by Unwin,
suggesting the skelopatagia of *Sordes* was actually a
cruropatagium, but then refuted based on distortion in
the skeletons and impressions of the pterosaur, so I'm
not sure what to think. Unwin (1999) in TREE has
recently re-evaluated the brachiopatagia in pterosaurs
to suggest it was skelopatagial (bat-like) rather than
Clarification of terms:
brachiopatagium = patagium extending behind the arm
along the side of the trunk.
skelopatagium = patagium extending from the arm to
the shin (skeleis) or the ankle (tarsos); I don't
think the term "tarsopatagium" has been coined, but it
wouldn't appear to be functionally different from a
cruropatagium = patagium extending from the arm to
the knee (crus) or the thigh (femoris).
"Femoropatagium" may be a published term.
ischiopatagium = I'm using this term to denote a
simple brachiopatagium that did not extend down the
leg, but kept at the hip (ischos) or more proximal to
the arm, and may not have been published; there could
also be another term in use for it.
Peters or Unwin may be of some help. I liked the
flying *Tropeognathus*, and noted that "conventional"
*Ornithocheirus* snouts were used to denote females,
while the Criorhynch or Tropeognath snouts were used
for the males. Furthermore, there has been recent
developments in pterosaur phylogeny that suggest that
anhanguerids [also = criorhynchids] (with the crested
snouts) were synonymous with ornithocheirids based on
jaws (the teeth arrangement) and wings.
*Criorhynchus*, an english anhanguerid, has some
similarities to wings of species of *Ornithocheirus*
[and there were a lot named], and has also been
considered congeneric or -specific with Brazilian
*Tropeognathus.* Speaking on geographic bounds, I
would tentatively disagree, but like I said, I don't
study these critters much.
Other Comments on WWD:
As for the *Postosuchus* urinating, this was one of
the most amusing points I had that night, though I do
recognized its invalidity: the animal is bracketed
(sensu Witmer, 1995) by crocs and birds which do not
urinate or excrete waste in this manner. To suggest
that a postosuch would have is _really_ stretching
things! Besides, making territory on water-slick rocks
is also unlikely, as it doesn't persist.
Finally, the sauropod with the chelonian
"ovipositor" was .... unbeleivable. It solves one
problem, but I just don't buy it. These are
archosaurs, and sauropods _could_ reasonably squat,
and could also build mounds. Taphonomy of nest-sites
should clarify, and I need to go over the data from
Auca Mahuevo to see if there's corroboration or not.
Jaime "James" A. Headden
"Come the path that leads us to our fortune."
Qilong---is temporarily out of service.
Check back soon.
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