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re: Coelurosauravus: glider? or bluffer?



Jim Cunnigham wrote:

Pick up a pterosaur by its wingtips, and you will bust the phalanges.
They
won't carry the weight of the animal as a concentrated load at the tips.

dp: I'm thinking of pterosaurs in the size range of the gliding lizards.
Probably no bigger than a man's hands. And if the wing tips are the
problem, perhaps we could hold one at mid digit for the same analogy.


some wrote about skull bones, mandibles and clavicles being dermal in
origin:

dp: yes, but you're going back to fish here.  In Coelurosauravus it's
like going back to dermal ossicles, like Stegosaurus or horned toad
spikes. Scales gone crazy.

some wrote of the human hand having similar metacarpal proportions.

dp: please stay on the same merry-go-round. Anything diapsid and
Permo-Triassic would be better. And  all other arboreal diapsids did not
adopt this pattern.

regarding the anterior process of the ilium and bipedalism: It only
takes a  tiny nubbin of an anterior process in extant lizards to put
them in the bipedal camp. Which makes it easier, if you like analogies,
to attribute bipedalism to species we will never meet. If analogies
don't work for you, then lots of arguments go belly up.

Nick Pharris wrote:

Speaking of such, what about the pectoral fin rays of flying fish?
These are
thin, bony rods not connected to the vertebral column but still strong
enough
for use in gliding--perhaps they would form a good analogy for the rods
of
_Coelurosauravus_?

Again, as in bats and birds, the fore limbs/fins of flying fish are
chained to internal bones and muscles, unlike the skin of
Coelurosauravus.

Anyway, this was all just a thought starter. Something to tuck under
your hat and a reminder to question all assertions, especially those
made by me.

On another subject: I looked at the pes of Eudibamus, the purported
Permian biped. It looks like it does have everything a bipedal lizardy
reptile would need, except that the pes is so incredibly asymmetric that
Eudibamus would essentially be running on toe four alone. Not sure that
Permian diapsids would be ready for this, but I'm not totally
discounting it. A quick review of Bruce Jayne's videos shows that
typically a few more toes touch ground in the bipedal lizards. What's
interesting, though, if you create a 3D Eudibamus pes in a typical
lizard walking pose you can get PILs (parallel interphalangeal lines)
through all the toes in typical fashion in a very low, belly-dragging
quadrupedal pose.

Maybe it swung both ways.

Best to all,

David Peters

PS. I've been waiting for news and reviews about SVP. I've heard general
comments, mostly along the lines of "nothing earth-shattering."

Any views or opinions to share?