DM wrote:
Pterosaurs are front-heavy, so the foot
prints are expected to vanish in higher sediment layers than the hand
prints.
Not so. Check out pterosaur info. com > behaviors for an animation of a
walking pterosaur that actually fits the tracks. It's essentially
bipedal using its forelimbs as canes. And, if you can imagine using a
cane at the beach, you'll understand why the forelimbs press a little
deeper. Less surface area.
DM; Pterosaur walks on soft mud on all fours, many layers of
mud get deformed, the top layers erode away, and one of the underprint
layers ends up being published.
In every case? Seems unreasonable.
DM wrote:
Maybe that's where the multiple naris comes in.
It does not exist. It is a misinterpretation of cracks in the fossil.
Several people have pointed this out onlist.
No. They haven't. Not with pictures. And funny that the cracks form
identical phylogenetic patterns. That's unreasonable.
DM wrote:
Why? Jim has pointed out that it's physically impossible. The only worth
of this idea is that many of us have learned a bit more about basic
aerodynamics/biomechanics.
I join one and all in my respect for Jim's abilities. And yet, even he
has not come back from the Cretaceous with a butterfuly on his boot
sole. Some things are yet to be discovered. Some things are worth
considering other options. Tell me David, if _some_ poling marks turn
out to be primary ichnites, does that change any of your hypotheses?
David Peters
St. Louis