Re: "Flight theory has legs"

["Jaime A. Headden" <qilongia@yahoo.com>]

Graydon (oak@uniserve.com) wrote:
<Everything I've seen about dromeosaur feet indicates that they can't do
that; hallux isn't reversed, toes three and four don't curl under, etc.
You could maybe have a scenario where you get one sickle claw stuck and
then use the other one, repeat as necessary or convenient, but that seems
implausible; those claws are slicers rather than (rounder cross-section)
anchors.>

  I would like to know what would not permit the dromaeosaurid pes from
"curling under" given that *Microraptor gui* and NGMC 91 show exactly
this, the former more so than the latter. And no data shows us precisely
HOW far this could occur. Mounted skeletons of *Deinonychus* show a curled
pes, but I do not think this is based on any actual close-fit study of the
articular surfaces but rather to approximate the avian pes (birds when
they lift their foot tend to curl the toes underneath as a result of the
"relaxation" of the crural tendons). The tendency of modern dinosaur foot
postyre stems from almost exclusively restorations by Paul in the years
around 1988 where the pes is modelled after large ratires (even though
small ratites like kiwis curl their toes) that elevate the distal ends of
the toes.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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