[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: origin of bats/reply 2 to TMK

David Marjanovic (david.marjanovic@gmx.at) wrote:

<By "wing" I mean "wing feathers" -- remiges. Ostriches have wings...>

  But "wing feathers" can't include just coverts or contours, or even, any 
feather on the arm itself? The term "wing feather" is only compounding the 
issue of using the term wing, poorly in this case, in my opinion. I am not sure 
that a loose use of the term for an animal whose aerodynamic capabilities have 
never been assessed for the arm structures which imply a particular 
functionality of the arms is useful.

  In an earlier discussion on this topic, I argued possible functionality in 
*Archaeopteryx* arms, which have primaries and secondaries, can be elevated 
above the horizontal at the shoulder, can perform an approximation of the 
flight stroke to a reasonable degree (so we assume), and had limb proportions 
of a "flier" in so far that the forelimb is just a tad longer than the hindlimb 
in full extension. When the leg is postioned in walking and or running 
positions, and the arm is fully extended (as at the end of the extension of the 
wing during a "flight stroke"), it WILL be longer than the leg. Yet it wasn't a 
tree-hugger based on the habitat, so we must assume it was doing something with 
the arm, either laterally or with limited glide capability.

  It is also not neccessary to my understanding for there to be trees for 
Archie to possess arboreal characteristic, if say, it developed initial 
arboreality to cliff-jumping or climbing tall rocks. This may result in 
different proportions of the claws (straighter than curved, for example, but 
this is highly hypothetical).