RE: The origin of flight: from the water up (not TOO long)

["Edels" <edels@email.msn.com>]

A couple of replies in one (I intended to send this this morning, but could
not finish):

I had said: "Archie specimens [copies] that I've seen do not show
        the post-mortem curvature that appears in some dinosaurs -
        i.e. where the neck curls towards the back and the tail
        curls towards the front - toward each other over the back)."

Dan Varner said: "They do show that post-mortem curvature."

**For additional clarity to my statement - The tendons and muscles that
support the neck (and those that support the tail) have a tendency to curve
post-mortem in the way I described before.  Archie shows that curvature in
the neck, but the tail appears to be straight (see _Compsognathus_ specimen
for comparison).  Note that one specimen shows the tail bending the other
way - i.e. down towards the feet.  I'm not sure if this indicates that (in
Archie):
        1)      The tail was so stiff that it didn't bend, even after death.
        2)      The muscles/tendons in the tail were not as strong as those in
                the neck, and would not curve the tail.
        3)      The muscles in the tail were not for the normal purpose in
                most small saurischians (i.e. suspending the tail), but
                possible for more controlled movement.
        4)      It's just a preservational quirk.  :-)
                [E.g. the tail was buried quicker than the rest of the body, 
pinning it
down].


I had said: "and the tail feathers do not appear to be solidly interlinked.
"

Ralph Miller III said: "The feathers appear to hold together as well as
modern bird feathers do,
indicating that the barbs were held together with barbules.  And none of the
feathers is out of place."

**I meant that the tail feathers weren't *especially* reinforced in their
linkage, which, to me, would indicate that the tail wasn't especially stiff.
(I like Jaime's description of the tail feathers as probably 'fluffing-up'
like a squirrel's [or like a frightened cat's]).

**As to the problem of the apparent symmetry of the _Archaeopteryx_ feathers
(barring the solitary feather found by itself), Jim Cunningham has already
answered that - except for the question of how strong/stiff the feather
shafts were.  It seems to me that the feathers were sufficient to allow
Archie to fly, albeit somewhat awkwardly (based on our modern view of
flying).


**I also meant that even when it was assumed that _Archaeopteryx_ was
ectothermic, he could fly - but only for a short time.  My personal ideas
are that Archie was endothermic, and therefore could fly for a longer period
of time, and not be debilitated by the effort.  He probably flew for short
periods, probably not more than 2 or 3 minutes at a time (in fact, I'd guess
that 3 minutes would be the maximum flight time).

Also, Reichel's _Archaeopteryx_ is great!  It's how I've usually pictured
it.

Allan Edels