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Re: vaulting pterosaur launch, questions
> > Sorry to switch focus from pterosaurs to birds, but
> how do you picture
> > _Archaeopteryx_ getting itself airborne from terra
> firma? By leaping
> > from a standstill off the ground?
I would be very interested in knowing what sort of environment pterosaurs and
archaeopteryx's ancestors evolved in.
I don't know how the later ones started flying (birds today will both do a
running takeoff, or just leap into the air), but I highly doubt the first ones
to begin to fly just leapt into the air.
Going away from paleontology, and into aviation:
Birds always take off into the wind, a 9 mph wind would be enough to make up
the difference between the 2 m/s running speed, and 6 m/s stall speed.
The local weather and terrain can dramatically effect how easy it is to fly.
Perhaps this Tree vs Ground debate is overestimating the requirements for
flight, and ignoring the situations where I personally find it to be easiest to
Certainly, windy coastal dunes or cliffs would allow very easy flight without
the need to run anywhere near flying speed, or flap. It is at coastal dunes
that humans were first able to reliable practice flight- first at Kitty Hawk
with the Wright brothers, and then southern california beaches with
Early hang-gliders had horrendous glide ratios (like 4:1), and pretty bad sink
rates- but could still soar coastal dunes with sufficient wind. If I recall,
that was about the estimated glide ratio of Microraptor (which occurs after
Archaeopteryx, so I'm assuming the Dromeosaur linage is secondarily flightless).
I don't know how bats evolved, and the numerous arboreal gliding animals do
seem to strongly hint that perhaps an arboreal origin is likely. How would an
animal transition from gliding flight between trees, to powered flight?
I wonder if there were any forests that went right up to the beach with coastal
cliffs/dunes when and where pterosaurs/bats/birds evolved.
Such an arboreal glider should be able to fly in the ridge lift, and could then
perhaps develop further flight adaptations.
I learned to fly hanggliders at coastal dunes, flying there is super easy - I
can run nowhere near fast enough to get off the ground with my glider, doesn't
stop me from flying.
If you are interested in seeing just how "easy" flight is at coastal dunes, you
might want to check out these videos on youtube showing real examples of
completely unpowered coastal soaring in aircraft with sink rates and glide
ratios far worse than the majority of birds:
More videos if any of you care to see them:
And the following videos have more efficient Glider's, that also have higher